diff --git a/src/main/java/io/mycat/route/impl/DruidMycatRouteStrategy.java b/src/main/java/io/mycat/route/impl/DruidMycatRouteStrategy.java
index ba33f1e0c..9f6a1684f 100644
--- a/src/main/java/io/mycat/route/impl/DruidMycatRouteStrategy.java
+++ b/src/main/java/io/mycat/route/impl/DruidMycatRouteStrategy.java
@@ -1,756 +1,767 @@
-package io.mycat.route.impl;
-
-import java.sql.SQLNonTransientException;
-import java.sql.SQLSyntaxErrorException;
-import java.util.HashMap;
-import java.util.HashSet;
-import java.util.Iterator;
-import java.util.List;
-import java.util.Map;
-import java.util.Set;
-import java.util.SortedSet;
-import java.util.TreeSet;
-
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
-
-import com.alibaba.druid.sql.SQLUtils;
-import com.alibaba.druid.sql.ast.SQLObject;
-import com.alibaba.druid.sql.ast.SQLStatement;
-import com.alibaba.druid.sql.ast.expr.SQLAllExpr;
-import com.alibaba.druid.sql.ast.expr.SQLBinaryOpExpr;
-import com.alibaba.druid.sql.ast.expr.SQLExistsExpr;
-import com.alibaba.druid.sql.ast.expr.SQLIdentifierExpr;
-import com.alibaba.druid.sql.ast.expr.SQLInSubQueryExpr;
-import com.alibaba.druid.sql.ast.expr.SQLQueryExpr;
-import com.alibaba.druid.sql.ast.statement.SQLDeleteStatement;
-import com.alibaba.druid.sql.ast.statement.SQLExprTableSource;
-import com.alibaba.druid.sql.ast.statement.SQLInsertStatement;
-import com.alibaba.druid.sql.ast.statement.SQLSelect;
-import com.alibaba.druid.sql.ast.statement.SQLSelectQuery;
-import com.alibaba.druid.sql.ast.statement.SQLSelectStatement;
-import com.alibaba.druid.sql.ast.statement.SQLTableSource;
-import com.alibaba.druid.sql.ast.statement.SQLUpdateStatement;
-import com.alibaba.druid.sql.dialect.mysql.ast.statement.MySqlInsertStatement;
-import com.alibaba.druid.sql.dialect.mysql.ast.statement.MySqlReplaceStatement;
-import com.alibaba.druid.sql.dialect.mysql.ast.statement.MySqlSelectQueryBlock;
-import com.alibaba.druid.sql.dialect.mysql.parser.MySqlStatementParser;
-import com.alibaba.druid.sql.parser.SQLStatementParser;
-import com.alibaba.druid.stat.TableStat.Relationship;
-import com.google.common.base.Strings;
-
-import io.mycat.MycatServer;
-import io.mycat.backend.mysql.nio.handler.MiddlerQueryResultHandler;
-import io.mycat.backend.mysql.nio.handler.MiddlerResultHandler;
-import io.mycat.backend.mysql.nio.handler.SecondHandler;
-import io.mycat.cache.LayerCachePool;
-import io.mycat.config.ErrorCode;
-import io.mycat.config.model.SchemaConfig;
-import io.mycat.config.model.TableConfig;
-import io.mycat.config.model.rule.RuleConfig;
-import io.mycat.route.RouteResultset;
-import io.mycat.route.RouteResultsetNode;
-import io.mycat.route.function.SlotFunction;
-import io.mycat.route.impl.middlerResultStrategy.BinaryOpResultHandler;
-import io.mycat.route.impl.middlerResultStrategy.InSubQueryResultHandler;
-import io.mycat.route.impl.middlerResultStrategy.RouteMiddlerReaultHandler;
-import io.mycat.route.impl.middlerResultStrategy.SQLAllResultHandler;
-import io.mycat.route.impl.middlerResultStrategy.SQLExistsResultHandler;
-import io.mycat.route.impl.middlerResultStrategy.SQLQueryResultHandler;
-import io.mycat.route.parser.druid.DruidParser;
-import io.mycat.route.parser.druid.DruidParserFactory;
-import io.mycat.route.parser.druid.DruidShardingParseInfo;
-import io.mycat.route.parser.druid.MycatSchemaStatVisitor;
-import io.mycat.route.parser.druid.MycatStatementParser;
-import io.mycat.route.parser.druid.RouteCalculateUnit;
-import io.mycat.route.parser.util.ParseUtil;
-import io.mycat.route.util.RouterUtil;
-import io.mycat.server.NonBlockingSession;
-import io.mycat.server.ServerConnection;
-import io.mycat.server.parser.ServerParse;
-
-public class DruidMycatRouteStrategy extends AbstractRouteStrategy {
-	
-	public static final Logger LOGGER = LoggerFactory.getLogger(DruidMycatRouteStrategy.class);
-	
-	private static Map<Class<?>,RouteMiddlerReaultHandler> middlerResultHandler = new HashMap<>();
-	
-	static{
-		middlerResultHandler.put(SQLQueryExpr.class, new SQLQueryResultHandler());
-		middlerResultHandler.put(SQLBinaryOpExpr.class, new BinaryOpResultHandler());
-		middlerResultHandler.put(SQLInSubQueryExpr.class, new InSubQueryResultHandler());
-		middlerResultHandler.put(SQLExistsExpr.class, new SQLExistsResultHandler());
-		middlerResultHandler.put(SQLAllExpr.class, new SQLAllResultHandler());
-	}
-	
-	
-	@Override
-	public RouteResultset routeNormalSqlWithAST(SchemaConfig schema,
-			String stmt, RouteResultset rrs,String charset,
-			LayerCachePool cachePool,int sqlType,ServerConnection sc) throws SQLNonTransientException {
-		
-		/**
-		 *  只有mysql时只支持mysql语法
-		 */
-		SQLStatementParser parser = null;
-		if (schema.isNeedSupportMultiDBType()) {
-			parser = new MycatStatementParser(stmt);
-		} else {
-			parser = new MySqlStatementParser(stmt); 
-		}
-
-		MycatSchemaStatVisitor visitor = null;
-		SQLStatement statement;
-		
-		/**
-		 * 解析出现问题统一抛SQL语法错误
-		 */
-		try {
-			statement = parser.parseStatement();
-            visitor = new MycatSchemaStatVisitor();
-		} catch (Exception t) {
-	        LOGGER.error("DruidMycatRouteStrategyError", t);
-			throw new SQLSyntaxErrorException(t);
-		}
-
-		/**
-		 * 检验unsupported statement
-		 */
-		checkUnSupportedStatement(statement);
-
-		DruidParser druidParser = DruidParserFactory.create(schema, statement, visitor);
-		druidParser.parser(schema, rrs, statement, stmt,cachePool,visitor);
-		DruidShardingParseInfo ctx=  druidParser.getCtx() ;
-		rrs.setTables(ctx.getTables());
-		
-		if(visitor.isSubqueryRelationOr()){
-			String err = "In subQuery,the or condition is not supported.";
-			LOGGER.error(err);
-			throw new SQLSyntaxErrorException(err);
-		}
-		
-		/* 按照以下情况路由
-			1.2.1 可以直接路由.
-       		1.2.2 两个表夸库join的sql.调用calat
-       		1.2.3 需要先执行subquery 的sql.把subquery拆分出来.获取结果后,与outerquery
-		 */
-		
-		//add huangyiming 分片规则不一样的且表中带查询条件的则走Catlet
-		List<String> tables = ctx.getTables();
-		SchemaConfig schemaConf = MycatServer.getInstance().getConfig().getSchemas().get(schema.getName());
-		int index = 0;
-		RuleConfig firstRule = null;
-		boolean directRoute = true;
-		Set<String> firstDataNodes = new HashSet<String>();
-		Map<String, TableConfig> tconfigs = schemaConf==null?null:schemaConf.getTables();
-		
-		Map<String,RuleConfig> rulemap = new HashMap<>();
-		if(tconfigs!=null){	
-	        for(String tableName : tables){
-	            TableConfig tc =  tconfigs.get(tableName);
-	            if(tc == null){
-	              //add 别名中取
-	              Map<String, String> tableAliasMap = ctx.getTableAliasMap();
-	              if(tableAliasMap !=null && tableAliasMap.get(tableName) !=null){
-	                tc = schemaConf.getTables().get(tableAliasMap.get(tableName));
-	              }
-	            }
-
-	            if(index == 0){
-	            	 if(tc !=null){
-		                firstRule=  tc.getRule();
-						//没有指定分片规则时,不做处理
-		                if(firstRule==null){
-		                	continue;
-		                }
-		                firstDataNodes.addAll(tc.getDataNodes());
-		                rulemap.put(tc.getName(), firstRule);
-	            	 }
-	            }else{
-	                if(tc !=null){
-	                  //ER关系表的时候是可能存在字表中没有tablerule的情况,所以加上判断
-	                    RuleConfig ruleCfg = tc.getRule();
-	                    if(ruleCfg==null){  //没有指定分片规则时,不做处理
-	                    	continue;
-	                    }
-	                    Set<String> dataNodes = new HashSet<String>();
-	                    dataNodes.addAll(tc.getDataNodes());
-	                    rulemap.put(tc.getName(), ruleCfg);
-	                    //如果匹配规则不相同或者分片的datanode不相同则需要走子查询处理
-	                    if(firstRule!=null&&((ruleCfg !=null && !ruleCfg.getRuleAlgorithm().equals(firstRule.getRuleAlgorithm()) )||( !dataNodes.equals(firstDataNodes)))){
-	                      directRoute = false;
-	                      break;
-	                    }
-	                }
-	            }
-	            index++;
-	        }
-		} 
-		
-		RouteResultset rrsResult = rrs;
-		if(directRoute){ //直接路由
-			if(!RouterUtil.isAllGlobalTable(ctx, schemaConf)){
-				if(rulemap.size()>1&&!checkRuleField(rulemap,visitor)){
-					String err = "In case of slice table,there is no rule field in the relationship condition!";
-					LOGGER.error(err);
-					throw new SQLSyntaxErrorException(err);
-				}
-			}
-			rrsResult = directRoute(rrs,ctx,schema,druidParser,statement,cachePool);
-		}else{
-			int subQuerySize = visitor.getSubQuerys().size();
-			if(subQuerySize==0&&ctx.getTables().size()==2){ //两表关联,考虑使用catlet
-			    if(!visitor.getRelationships().isEmpty()){
-			    	rrs.setCacheAble(false);
-			    	rrs.setFinishedRoute(true);
-			    	rrsResult = catletRoute(schema,ctx.getSql(),charset,sc);
-				}else{
-					rrsResult = directRoute(rrs,ctx,schema,druidParser,statement,cachePool);
-				}
-			}else if(subQuerySize==1){     //只涉及一张表的子查询,使用  MiddlerResultHandler 获取中间结果后,改写原有 sql 继续执行 TODO 后期可能会考虑多个子查询的情况.
-				SQLSelect sqlselect = visitor.getSubQuerys().iterator().next();
-				if(!visitor.getRelationships().isEmpty()){     // 当 inner query  和 outer  query  有关联条件时,暂不支持
-					String err = "In case of slice table,sql have different rules,the relationship condition is not supported.";
-					LOGGER.error(err);
-					throw new SQLSyntaxErrorException(err);
-				}else{
-					SQLSelectQuery sqlSelectQuery = sqlselect.getQuery();
-					if(((MySqlSelectQueryBlock)sqlSelectQuery).getFrom() instanceof SQLExprTableSource) {
-						rrs.setCacheAble(false);
-						rrs.setFinishedRoute(true);
-						rrsResult = middlerResultRoute(schema,charset,sqlselect,sqlType,statement,sc);
-					}
-				}
-			}else if(subQuerySize >=2){
-				String err = "In case of slice table,sql has different rules,currently only one subQuery is supported.";
-				LOGGER.error(err);
-				throw new SQLSyntaxErrorException(err);
-			}
-		}
-		return rrsResult;
-	}
-	
-	/**
-	 * 子查询中存在关联查询的情况下,检查关联字段是否是分片字段
-	 * @param rulemap
-	 * @param ships
-	 * @return
-	 */
-	private boolean checkRuleField(Map<String,RuleConfig> rulemap,MycatSchemaStatVisitor visitor){
-		
-		if(!MycatServer.getInstance().getConfig().getSystem().isSubqueryRelationshipCheck()){
-			return true;
-		}
-		
-		Set<Relationship> ships = visitor.getRelationships();
-		Iterator<Relationship> iter = ships.iterator();
-		while(iter.hasNext()){
-			Relationship ship = iter.next();
-			String lefttable = ship.getLeft().getTable().toUpperCase();
-			String righttable = ship.getRight().getTable().toUpperCase();
-			// 如果是同一个表中的关联条件,不做处理
-			if(lefttable.equals(righttable)){
-				return true;
-			}
-			RuleConfig leftconfig = rulemap.get(lefttable);
-			RuleConfig rightconfig = rulemap.get(righttable);
-			
-			if(null!=leftconfig&&null!=rightconfig
-					&&leftconfig.equals(rightconfig)
-					&&leftconfig.getColumn().equals(ship.getLeft().getName().toUpperCase())
-					&&rightconfig.getColumn().equals(ship.getRight().getName().toUpperCase())){
-				return true;
-			}
-		}
-		return false;
-	}
-	
-	private RouteResultset middlerResultRoute(final SchemaConfig schema,final String charset,final SQLSelect sqlselect,
-												final int sqlType,final SQLStatement statement,final ServerConnection sc){
-		
-		final String middlesql = SQLUtils.toMySqlString(sqlselect);
-		
-    	MiddlerResultHandler<String> middlerResultHandler =  new MiddlerQueryResultHandler<>(new SecondHandler() {						 
-				@Override
-				public void doExecute(List param) {
-					sc.getSession2().setMiddlerResultHandler(null);
-					String sqls = null;
-					// 路由计算
-					RouteResultset rrs = null;
-					try {
-						
-						sqls = buildSql(statement,sqlselect,param);
-						rrs = MycatServer
-								.getInstance()
-								.getRouterservice()
-								.route(MycatServer.getInstance().getConfig().getSystem(),
-										schema, sqlType,sqls.toLowerCase(), charset,sc );
-
-					} catch (Exception e) {
-						StringBuilder s = new StringBuilder();
-						LOGGER.warn(s.append(this).append(sqls).toString() + " err:" + e.toString(),e);
-						String msg = e.getMessage();
-						sc.writeErrMessage(ErrorCode.ER_PARSE_ERROR, msg == null ? e.getClass().getSimpleName() : msg);
-						return;
-					}
-					NonBlockingSession noBlockSession =  new NonBlockingSession(sc.getSession2().getSource());
-					noBlockSession.setMiddlerResultHandler(null);
-					//session的预编译标示传递
-					noBlockSession.setPrepared(sc.getSession2().isPrepared());
-					if (rrs != null) {						
-						noBlockSession.setCanClose(false);
-						noBlockSession.execute(rrs, ServerParse.SELECT);
-					}
-				}
-			} );
-    	sc.getSession2().setMiddlerResultHandler(middlerResultHandler);
-    	sc.getSession2().setCanClose(false);
-    
-		// 路由计算
-		RouteResultset rrs = null;
-		try {
-			rrs = MycatServer
-					.getInstance()
-					.getRouterservice()
-					.route(MycatServer.getInstance().getConfig().getSystem(),
-							schema, ServerParse.SELECT, middlesql, charset, sc);
-	
-		} catch (Exception e) {
-			StringBuilder s = new StringBuilder();
-			LOGGER.warn(s.append(this).append(middlesql).toString() + " err:" + e.toString(),e);
-			String msg = e.getMessage();
-			sc.writeErrMessage(ErrorCode.ER_PARSE_ERROR, msg == null ? e.getClass().getSimpleName() : msg);
-			return null;
-		}
-		
-		if(rrs!=null){
-			rrs.setCacheAble(false);
-		}
-		return rrs;
-	}
-	
-	/**
-	 * 获取子查询执行结果后,改写原始sql 继续执行.
-	 * @param statement
-	 * @param sqlselect
-	 * @param param
-	 * @return
-	 */
-	private String buildSql(SQLStatement statement,SQLSelect sqlselect,List param){
-
-		SQLObject parent = sqlselect.getParent();
-		RouteMiddlerReaultHandler handler = middlerResultHandler.get(parent.getClass());
-		if(handler==null){
-			throw new UnsupportedOperationException(parent.getClass()+" current is not supported ");
-		}
-		return handler.dohandler(statement, sqlselect, parent, param);
-	}
-	
-	/**
-	 * 两个表的情况，catlet
-	 * @param schema
-	 * @param stmt
-	 * @param charset
-	 * @param sc
-	 * @return
-	 */
-	private RouteResultset catletRoute(SchemaConfig schema,String stmt,String charset,ServerConnection sc){
-		RouteResultset rrs = null;
-		try {
-			rrs = MycatServer
-					.getInstance()
-					.getRouterservice()
-					.route(MycatServer.getInstance().getConfig().getSystem(),
-							schema, ServerParse.SELECT, "/*!mycat:catlet=io.mycat.catlets.ShareJoin */ "+stmt, charset, sc);
-			
-		}catch(Exception e){
-			
-		}
-		return rrs;
-	}
-	
-	/**
-	 *  直接结果路由
-	 * @param rrs
-	 * @param ctx
-	 * @param schema
-	 * @param druidParser
-	 * @param statement
-	 * @param cachePool
-	 * @return
-	 * @throws SQLNonTransientException
-	 */
-	private RouteResultset directRoute(RouteResultset rrs,DruidShardingParseInfo ctx,SchemaConfig schema,
-										DruidParser druidParser,SQLStatement statement,LayerCachePool cachePool) throws SQLNonTransientException{
-		
-		//改写sql：如insert语句主键自增长, 在直接结果路由的情况下,进行sql 改写处理
-		druidParser.changeSql(schema, rrs, statement,cachePool);
-		
-		/**
-		 * DruidParser 解析过程中已完成了路由的直接返回
-		 */
-		if ( rrs.isFinishedRoute() ) {
-			return rrs;
-		}
-		
-		/**
-		 * 没有from的select语句或其他
-		 */
-        if((ctx.getTables() == null || ctx.getTables().size() == 0)&&(ctx.getTableAliasMap()==null||ctx.getTableAliasMap().isEmpty()))
-        {
-		    return RouterUtil.routeToSingleNode(rrs, schema.getRandomDataNode(), druidParser.getCtx().getSql());
-		}
-
-		if(druidParser.getCtx().getRouteCalculateUnits().size() == 0) {
-			RouteCalculateUnit routeCalculateUnit = new RouteCalculateUnit();
-			druidParser.getCtx().addRouteCalculateUnit(routeCalculateUnit);
-		}
-		
-		SortedSet<RouteResultsetNode> nodeSet = new TreeSet<RouteResultsetNode>();
-		boolean isAllGlobalTable = RouterUtil.isAllGlobalTable(ctx, schema);
-		for(RouteCalculateUnit unit: druidParser.getCtx().getRouteCalculateUnits()) {
-			RouteResultset rrsTmp = RouterUtil.tryRouteForTables(schema, druidParser.getCtx(), unit, rrs, isSelect(statement), cachePool);
-			if(rrsTmp != null&&rrsTmp.getNodes()!=null) {
-				for(RouteResultsetNode node :rrsTmp.getNodes()) {
-					nodeSet.add(node);
-				}
-			}
-			if(isAllGlobalTable) {//都是全局表时只计算一遍路由
-				break;
-			}
-		}
-		
-		RouteResultsetNode[] nodes = new RouteResultsetNode[nodeSet.size()];
-		int i = 0;
-		for (RouteResultsetNode aNodeSet : nodeSet) {
-			nodes[i] = aNodeSet;
-			  if(statement instanceof MySqlInsertStatement &&ctx.getTables().size()==1&&schema.getTables().containsKey(ctx.getTables().get(0))) {
-				  RuleConfig rule = schema.getTables().get(ctx.getTables().get(0)).getRule();
-				  if(rule!=null&&  rule.getRuleAlgorithm() instanceof SlotFunction){
-					 aNodeSet.setStatement(ParseUtil.changeInsertAddSlot(aNodeSet.getStatement(),aNodeSet.getSlot()));
-				  }
-			  }
-			i++;
-		}		
-		rrs.setNodes(nodes);		
-		
-		//分表
-		/**
-		 *  subTables="t_order$1-2,t_order3"
-		 *目前分表 1.6 开始支持 幵丏 dataNode 在分表条件下只能配置一个，分表条件下不支持join。
-		 */
-		if(rrs.isDistTable()){
-			return this.routeDisTable(statement,rrs);
-		}
-		return rrs;
-	}
-	
-	private SQLExprTableSource getDisTable(SQLTableSource tableSource,RouteResultsetNode node) throws SQLSyntaxErrorException{
-		if(node.getSubTableName()==null){
-			String msg = " sub table not exists for " + node.getName() + " on " + tableSource;
-			LOGGER.error("DruidMycatRouteStrategyError " + msg);
-			throw new SQLSyntaxErrorException(msg);
-		}
-		
-		SQLIdentifierExpr sqlIdentifierExpr = new SQLIdentifierExpr();
-		sqlIdentifierExpr.setParent(tableSource.getParent());
-		sqlIdentifierExpr.setName(node.getSubTableName());
-		SQLExprTableSource from2 = new SQLExprTableSource(sqlIdentifierExpr);
-		return from2;
-	}
-	
-	private RouteResultset routeDisTable(SQLStatement statement, RouteResultset rrs) throws SQLSyntaxErrorException{
-		SQLTableSource tableSource = null;
-		if(statement instanceof SQLInsertStatement) {
-			SQLInsertStatement insertStatement = (SQLInsertStatement) statement;
-			tableSource = insertStatement.getTableSource();
-			for (RouteResultsetNode node : rrs.getNodes()) {
-				SQLExprTableSource from2 = getDisTable(tableSource, node);
-				insertStatement.setTableSource(from2);
-				node.setStatement(insertStatement.toString());
-	        }
-		}
-		if(statement instanceof SQLDeleteStatement) {
-			SQLDeleteStatement deleteStatement = (SQLDeleteStatement) statement;
-			tableSource = deleteStatement.getTableSource();
-			for (RouteResultsetNode node : rrs.getNodes()) {
-				SQLExprTableSource from2 = getDisTable(tableSource, node);
-				deleteStatement.setTableSource(from2);
-				node.setStatement(deleteStatement.toString());
-	        }
-		}
-		if(statement instanceof SQLUpdateStatement) {
-			SQLUpdateStatement updateStatement = (SQLUpdateStatement) statement;
-			tableSource = updateStatement.getTableSource();
-			for (RouteResultsetNode node : rrs.getNodes()) {
-				SQLExprTableSource from2 = getDisTable(tableSource, node);
-				updateStatement.setTableSource(from2);
-				node.setStatement(updateStatement.toString());
-	        }
-		}
-		
-		return rrs;
-	}
-
-	/**
-	 * SELECT 语句
-	 */
-    private boolean isSelect(SQLStatement statement) {
-		if(statement instanceof SQLSelectStatement) {
-			return true;
-		}
-		return false;
-	}
-	
-	/**
-	 * 检验不支持的SQLStatement类型 ：不支持的类型直接抛SQLSyntaxErrorException异常
-	 * @param statement
-	 * @throws SQLSyntaxErrorException
-	 */
-	private void checkUnSupportedStatement(SQLStatement statement) throws SQLSyntaxErrorException {
-		//不支持replace语句
-		if(statement instanceof MySqlReplaceStatement) {
-			throw new SQLSyntaxErrorException(" ReplaceStatement can't be supported,use insert into ...on duplicate key update... instead ");
-		}
-	}
-	
-	/**
-	 * 分析 SHOW SQL
-	 */
-	@Override
-	public RouteResultset analyseShowSQL(SchemaConfig schema,
-			RouteResultset rrs, String stmt) throws SQLSyntaxErrorException {
-		
-		String upStmt = stmt.toUpperCase();
-		int tabInd = upStmt.indexOf(" TABLES");
-		if (tabInd > 0) {// show tables
-			int[] nextPost = RouterUtil.getSpecPos(upStmt, 0);
-			if (nextPost[0] > 0) {// remove db info
-				int end = RouterUtil.getSpecEndPos(upStmt, tabInd);
-				if (upStmt.indexOf(" FULL") > 0) {
-					stmt = "SHOW FULL TABLES" + stmt.substring(end);
-				} else {
-					stmt = "SHOW TABLES" + stmt.substring(end);
-				}
-			}
-          String defaultNode=  schema.getDataNode();
-            if(!Strings.isNullOrEmpty(defaultNode))
-            {
-             return    RouterUtil.routeToSingleNode(rrs, defaultNode, stmt);
-            }
-			return RouterUtil.routeToMultiNode(false, rrs, schema.getMetaDataNodes(), stmt);
-		}
-		
-		/**
-		 *  show index or column
-		 */
-		int[] indx = RouterUtil.getSpecPos(upStmt, 0);
-		if (indx[0] > 0) {
-			/**
-			 *  has table
-			 */
-			int[] repPos = { indx[0] + indx[1], 0 };
-			String tableName = RouterUtil.getShowTableName(stmt, repPos);
-			/**
-			 *  IN DB pattern
-			 */
-			int[] indx2 = RouterUtil.getSpecPos(upStmt, indx[0] + indx[1] + 1);
-			if (indx2[0] > 0) {// find LIKE OR WHERE
-				repPos[1] = RouterUtil.getSpecEndPos(upStmt, indx2[0] + indx2[1]);
-
-			}
-			stmt = stmt.substring(0, indx[0]) + " FROM " + tableName + stmt.substring(repPos[1]);
-			RouterUtil.routeForTableMeta(rrs, schema, tableName, stmt);
-			return rrs;
-
-		}
-		
-		/**
-		 *  show create table tableName
-		 */
-		int[] createTabInd = RouterUtil.getCreateTablePos(upStmt, 0);
-		if (createTabInd[0] > 0) {
-			int tableNameIndex = createTabInd[0] + createTabInd[1];
-			if (upStmt.length() > tableNameIndex) {
-				String tableName = stmt.substring(tableNameIndex).trim();
-				int ind2 = tableName.indexOf('.');
-				if (ind2 > 0) {
-					tableName = tableName.substring(ind2 + 1);
-				}
-				RouterUtil.routeForTableMeta(rrs, schema, tableName, stmt);
-				return rrs;
-			}
-		}
-
-		return RouterUtil.routeToSingleNode(rrs, schema.getRandomDataNode(), stmt);
-	}
-	
-	
-//	/**
-//	 * 为一个表进行条件路由
-//	 * @param schema
-//	 * @param tablesAndConditions
-//	 * @param tablesRouteMap
-//	 * @throws SQLNonTransientException
-//	 */
-//	private static RouteResultset findRouteWithcConditionsForOneTable(SchemaConfig schema, RouteResultset rrs,
-//		Map<String, Set<ColumnRoutePair>> conditions, String tableName, String sql) throws SQLNonTransientException {
-//		boolean cache = rrs.isCacheAble();
-//	    //为分库表找路由
-//		tableName = tableName.toUpperCase();
-//		TableConfig tableConfig = schema.getTables().get(tableName);
-//		//全局表或者不分库的表略过（全局表后面再计算）
-//		if(tableConfig.isGlobalTable()) {
-//			return null;
-//		} else {//非全局表
-//			Set<String> routeSet = new HashSet<String>();
-//			String joinKey = tableConfig.getJoinKey();
-//			for(Map.Entry<String, Set<ColumnRoutePair>> condition : conditions.entrySet()) {
-//				String colName = condition.getKey();
-//				//条件字段是拆分字段
-//				if(colName.equals(tableConfig.getPartitionColumn())) {
-//					Set<ColumnRoutePair> columnPairs = condition.getValue();
-//					
-//					for(ColumnRoutePair pair : columnPairs) {
-//						if(pair.colValue != null) {
-//							Integer nodeIndex = tableConfig.getRule().getRuleAlgorithm().calculate(pair.colValue);
-//							if(nodeIndex == null) {
-//								String msg = "can't find any valid datanode :" + tableConfig.getName() 
-//										+ " -> " + tableConfig.getPartitionColumn() + " -> " + pair.colValue;
-//								LOGGER.warn(msg);
-//								throw new SQLNonTransientException(msg);
-//							}
-//							String node = tableConfig.getDataNodes().get(nodeIndex);
-//							if(node != null) {//找到一个路由节点
-//								routeSet.add(node);
-//							}
-//						}
-//						if(pair.rangeValue != null) {
-//							Integer[] nodeIndexs = tableConfig.getRule().getRuleAlgorithm()
-//									.calculateRange(pair.rangeValue.beginValue.toString(), pair.rangeValue.endValue.toString());
-//							for(Integer idx : nodeIndexs) {
-//								String node = tableConfig.getDataNodes().get(idx);
-//								if(node != null) {//找到一个路由节点
-//									routeSet.add(node);
-//								}
-//							}
-//						}
-//					}
-//				} else if(joinKey != null && joinKey.equals(colName)) {
-//					Set<String> dataNodeSet = RouterUtil.ruleCalculate(
-//							tableConfig.getParentTC(), condition.getValue());
-//					if (dataNodeSet.isEmpty()) {
-//						throw new SQLNonTransientException(
-//								"parent key can't find any valid datanode ");
-//					}
-//					if (LOGGER.isDebugEnabled()) {
-//						LOGGER.debug("found partion nodes (using parent partion rule directly) for child table to update  "
-//								+ Arrays.toString(dataNodeSet.toArray()) + " sql :" + sql);
-//					}
-//					if (dataNodeSet.size() > 1) {
-//						return RouterUtil.routeToMultiNode(rrs.isCacheAble(), rrs, schema.getAllDataNodes(), sql);
-//					} else {
-//						rrs.setCacheAble(true);
-//						return RouterUtil.routeToSingleNode(rrs, dataNodeSet.iterator().next(), sql);
-//					}
-//				} else {//条件字段不是拆分字段也不是join字段,略过
-//					continue;
-//					
-//				}
-//			}
-//			return RouterUtil.routeToMultiNode(cache, rrs, routeSet, sql);
-//			
-//		}
-//
-//	}
-
-	public RouteResultset routeSystemInfo(SchemaConfig schema, int sqlType,
-			String stmt, RouteResultset rrs) throws SQLSyntaxErrorException {
-		switch(sqlType){
-		case ServerParse.SHOW:// if origSQL is like show tables
-			return analyseShowSQL(schema, rrs, stmt);
-		case ServerParse.SELECT://if origSQL is like select @@
-			int index = stmt.indexOf("@@");
-			if(index > 0 && "SELECT".equals(stmt.substring(0, index).trim().toUpperCase())){
-				return analyseDoubleAtSgin(schema, rrs, stmt);
-			}
-			break;
-		case ServerParse.DESCRIBE:// if origSQL is meta SQL, such as describe table
-			int ind = stmt.indexOf(' ');
-			stmt = stmt.trim();
-			return analyseDescrSQL(schema, rrs, stmt, ind + 1);
-		}
-		return null;
-	}
-	
-	/**
-	 * 对Desc语句进行分析 返回数据路由集合
-	 * 	 * 
-	 * @param schema   				数据库名
-	 * @param rrs    				数据路由集合
-	 * @param stmt   				执行语句
-	 * @param ind    				第一个' '的位置
-	 * @return RouteResultset		(数据路由集合)
-	 * @author mycat
-	 */
-	private static RouteResultset analyseDescrSQL(SchemaConfig schema,
-			RouteResultset rrs, String stmt, int ind) {
-		
-		final String MATCHED_FEATURE = "DESCRIBE ";
-		final String MATCHED2_FEATURE = "DESC ";
-		int pos = 0;
-		while (pos < stmt.length()) {
-			char ch = stmt.charAt(pos);
-			// 忽略处理注释 /* */ BEN
-			if(ch == '/' &&  pos+4 < stmt.length() && stmt.charAt(pos+1) == '*') {
-				if(stmt.substring(pos+2).indexOf("*/") != -1) {
-					pos += stmt.substring(pos+2).indexOf("*/")+4;
-					continue;
-				} else {
-					// 不应该发生这类情况。
-					throw new IllegalArgumentException("sql 注释 语法错误");
-				}
-			} else if(ch == 'D'||ch == 'd') {
-				// 匹配 [describe ] 
-				if(pos+MATCHED_FEATURE.length() < stmt.length() && (stmt.substring(pos).toUpperCase().indexOf(MATCHED_FEATURE) != -1)) {
-					pos = pos + MATCHED_FEATURE.length();
-					break;
-				} else if(pos+MATCHED2_FEATURE.length() < stmt.length() && (stmt.substring(pos).toUpperCase().indexOf(MATCHED2_FEATURE) != -1)) {
-					pos = pos + MATCHED2_FEATURE.length();
-					break;
-				} else {
-					pos++;
-				}
-			}
-		}
-		
-		// 重置ind坐标。BEN GONG
-		ind = pos;		
-		int[] repPos = { ind, 0 };
-		String tableName = RouterUtil.getTableName(stmt, repPos);
-		
-		stmt = stmt.substring(0, ind) + tableName + stmt.substring(repPos[1]);
-		RouterUtil.routeForTableMeta(rrs, schema, tableName, stmt);
-		return rrs;
-	}
-	
-	/**
-	 * 根据执行语句判断数据路由
-	 * 
-	 * @param schema     			数据库名
-	 * @param rrs		  		 	数据路由集合
-	 * @param stmt		  	 		执行sql
-	 * @return RouteResultset		数据路由集合
-	 * @throws SQLSyntaxErrorException
-	 * @author mycat
-	 */
-	private RouteResultset analyseDoubleAtSgin(SchemaConfig schema,
-			RouteResultset rrs, String stmt) throws SQLSyntaxErrorException {		
-		String upStmt = stmt.toUpperCase();
-		int atSginInd = upStmt.indexOf(" @@");
-		if (atSginInd > 0) {
-			return RouterUtil.routeToMultiNode(false, rrs, schema.getMetaDataNodes(), stmt);
-		}
-		return RouterUtil.routeToSingleNode(rrs, schema.getRandomDataNode(), stmt);
-	}
+package io.mycat.route.impl;
+
+import java.sql.SQLNonTransientException;
+import java.sql.SQLSyntaxErrorException;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.Iterator;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+import java.util.SortedSet;
+import java.util.TreeSet;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import com.alibaba.druid.sql.SQLUtils;
+import com.alibaba.druid.sql.ast.SQLObject;
+import com.alibaba.druid.sql.ast.SQLStatement;
+import com.alibaba.druid.sql.ast.expr.SQLAllExpr;
+import com.alibaba.druid.sql.ast.expr.SQLBinaryOpExpr;
+import com.alibaba.druid.sql.ast.expr.SQLExistsExpr;
+import com.alibaba.druid.sql.ast.expr.SQLIdentifierExpr;
+import com.alibaba.druid.sql.ast.expr.SQLInSubQueryExpr;
+import com.alibaba.druid.sql.ast.expr.SQLQueryExpr;
+import com.alibaba.druid.sql.ast.statement.SQLDeleteStatement;
+import com.alibaba.druid.sql.ast.statement.SQLExprTableSource;
+import com.alibaba.druid.sql.ast.statement.SQLInsertStatement;
+import com.alibaba.druid.sql.ast.statement.SQLSelect;
+import com.alibaba.druid.sql.ast.statement.SQLSelectQuery;
+import com.alibaba.druid.sql.ast.statement.SQLSelectStatement;
+import com.alibaba.druid.sql.ast.statement.SQLTableSource;
+import com.alibaba.druid.sql.ast.statement.SQLUpdateStatement;
+import com.alibaba.druid.sql.dialect.mysql.ast.statement.MySqlInsertStatement;
+import com.alibaba.druid.sql.dialect.mysql.ast.statement.MySqlReplaceStatement;
+import com.alibaba.druid.sql.dialect.mysql.ast.statement.MySqlSelectQueryBlock;
+import com.alibaba.druid.sql.dialect.mysql.parser.MySqlStatementParser;
+import com.alibaba.druid.sql.parser.SQLStatementParser;
+import com.alibaba.druid.stat.TableStat.Relationship;
+import com.google.common.base.Strings;
+
+import io.mycat.MycatServer;
+import io.mycat.backend.mysql.nio.handler.MiddlerQueryResultHandler;
+import io.mycat.backend.mysql.nio.handler.MiddlerResultHandler;
+import io.mycat.backend.mysql.nio.handler.SecondHandler;
+import io.mycat.cache.LayerCachePool;
+import io.mycat.config.ErrorCode;
+import io.mycat.config.model.SchemaConfig;
+import io.mycat.config.model.TableConfig;
+import io.mycat.config.model.rule.RuleConfig;
+import io.mycat.route.RouteResultset;
+import io.mycat.route.RouteResultsetNode;
+import io.mycat.route.function.SlotFunction;
+import io.mycat.route.impl.middlerResultStrategy.BinaryOpResultHandler;
+import io.mycat.route.impl.middlerResultStrategy.InSubQueryResultHandler;
+import io.mycat.route.impl.middlerResultStrategy.RouteMiddlerReaultHandler;
+import io.mycat.route.impl.middlerResultStrategy.SQLAllResultHandler;
+import io.mycat.route.impl.middlerResultStrategy.SQLExistsResultHandler;
+import io.mycat.route.impl.middlerResultStrategy.SQLQueryResultHandler;
+import io.mycat.route.parser.druid.DruidParser;
+import io.mycat.route.parser.druid.DruidParserFactory;
+import io.mycat.route.parser.druid.DruidShardingParseInfo;
+import io.mycat.route.parser.druid.MycatSchemaStatVisitor;
+import io.mycat.route.parser.druid.MycatStatementParser;
+import io.mycat.route.parser.druid.RouteCalculateUnit;
+import io.mycat.route.parser.util.ParseUtil;
+import io.mycat.route.util.RouterUtil;
+import io.mycat.server.NonBlockingSession;
+import io.mycat.server.ServerConnection;
+import io.mycat.server.parser.ServerParse;
+
+public class DruidMycatRouteStrategy extends AbstractRouteStrategy {
+	
+	public static final Logger LOGGER = LoggerFactory.getLogger(DruidMycatRouteStrategy.class);
+	
+	private static Map<Class<?>,RouteMiddlerReaultHandler> middlerResultHandler = new HashMap<>();
+	
+	static{
+		middlerResultHandler.put(SQLQueryExpr.class, new SQLQueryResultHandler());
+		middlerResultHandler.put(SQLBinaryOpExpr.class, new BinaryOpResultHandler());
+		middlerResultHandler.put(SQLInSubQueryExpr.class, new InSubQueryResultHandler());
+		middlerResultHandler.put(SQLExistsExpr.class, new SQLExistsResultHandler());
+		middlerResultHandler.put(SQLAllExpr.class, new SQLAllResultHandler());
+	}
+	
+	
+	@Override
+	public RouteResultset routeNormalSqlWithAST(SchemaConfig schema,
+			String stmt, RouteResultset rrs,String charset,
+			LayerCachePool cachePool,int sqlType,ServerConnection sc) throws SQLNonTransientException {
+		
+		/**
+		 *  只有mysql时只支持mysql语法
+		 */
+		SQLStatementParser parser = null;
+		if (schema.isNeedSupportMultiDBType()) {
+			parser = new MycatStatementParser(stmt);
+		} else {
+			parser = new MySqlStatementParser(stmt); 
+		}
+
+		MycatSchemaStatVisitor visitor = null;
+		SQLStatement statement;
+		
+		/**
+		 * 解析出现问题统一抛SQL语法错误
+		 */
+		try {
+			statement = parser.parseStatement();
+            visitor = new MycatSchemaStatVisitor();
+		} catch (Exception t) {
+	        LOGGER.error("DruidMycatRouteStrategyError", t);
+			throw new SQLSyntaxErrorException(t);
+		}
+
+		/**
+		 * 检验unsupported statement
+		 */
+		checkUnSupportedStatement(statement);
+
+		DruidParser druidParser = DruidParserFactory.create(schema, statement, visitor);
+		druidParser.parser(schema, rrs, statement, stmt,cachePool,visitor);
+		DruidShardingParseInfo ctx=  druidParser.getCtx() ;
+		rrs.setTables(ctx.getTables());
+		
+		if(visitor.isSubqueryRelationOr()){
+			String err = "In subQuery,the or condition is not supported.";
+			LOGGER.error(err);
+			throw new SQLSyntaxErrorException(err);
+		}
+		
+		/* 按照以下情况路由
+			1.2.1 可以直接路由.
+       		1.2.2 两个表夸库join的sql.调用calat
+       		1.2.3 需要先执行subquery 的sql.把subquery拆分出来.获取结果后,与outerquery
+		 */
+		
+		//add huangyiming 分片规则不一样的且表中带查询条件的则走Catlet
+		List<String> tables = ctx.getTables();
+		SchemaConfig schemaConf = MycatServer.getInstance().getConfig().getSchemas().get(schema.getName());
+		int index = 0;
+		RuleConfig firstRule = null;
+		boolean directRoute = true;
+		Set<String> firstDataNodes = new HashSet<String>();
+		Map<String, TableConfig> tconfigs = schemaConf==null?null:schemaConf.getTables();
+		
+		Map<String,RuleConfig> rulemap = new HashMap<>();
+		if(tconfigs!=null){	
+	        for(String tableName : tables){
+	            TableConfig tc =  tconfigs.get(tableName);
+	            if(tc == null){
+	              //add 别名中取
+	              Map<String, String> tableAliasMap = ctx.getTableAliasMap();
+	              if(tableAliasMap !=null && tableAliasMap.get(tableName) !=null){
+	                tc = schemaConf.getTables().get(tableAliasMap.get(tableName));
+	              }
+	            }
+
+	            if(index == 0){
+	            	 if(tc !=null){
+		                firstRule=  tc.getRule();
+						//没有指定分片规则时,不做处理
+		                if(firstRule==null){
+		                	continue;
+		                }
+		                firstDataNodes.addAll(tc.getDataNodes());
+		                rulemap.put(tc.getName(), firstRule);
+	            	 }
+	            }else{
+	                if(tc !=null){
+	                  //ER关系表的时候是可能存在字表中没有tablerule的情况,所以加上判断
+	                    RuleConfig ruleCfg = tc.getRule();
+	                    if(ruleCfg==null){  //没有指定分片规则时,不做处理
+	                    	continue;
+	                    }
+	                    Set<String> dataNodes = new HashSet<String>();
+	                    dataNodes.addAll(tc.getDataNodes());
+	                    rulemap.put(tc.getName(), ruleCfg);
+	                    //如果匹配规则不相同或者分片的datanode不相同则需要走子查询处理
+	                    if(firstRule!=null&&((ruleCfg !=null && !ruleCfg.getRuleAlgorithm().equals(firstRule.getRuleAlgorithm()) )||( !dataNodes.equals(firstDataNodes)))){
+	                      directRoute = false;
+	                      break;
+	                    }
+	                }
+	            }
+	            index++;
+	        }
+		} 
+		
+		RouteResultset rrsResult = rrs;
+		if(directRoute){ //直接路由
+			if(!RouterUtil.isAllGlobalTable(ctx, schemaConf)){
+				if(rulemap.size()>1&&!checkRuleField(rulemap,visitor)){
+					String err = "In case of slice table,there is no rule field in the relationship condition!";
+					LOGGER.error(err);
+					throw new SQLSyntaxErrorException(err);
+				}
+			}
+			rrsResult = directRoute(rrs,ctx,schema,druidParser,statement,cachePool);
+		}else{
+			int subQuerySize = visitor.getSubQuerys().size();
+			if(subQuerySize==0&&ctx.getTables().size()==2){ //两表关联,考虑使用catlet
+			    if(!visitor.getRelationships().isEmpty()){
+			    	rrs.setCacheAble(false);
+			    	rrs.setFinishedRoute(true);
+			    	rrsResult = catletRoute(schema,ctx.getSql(),charset,sc);
+				}else{
+					rrsResult = directRoute(rrs,ctx,schema,druidParser,statement,cachePool);
+				}
+			}else if(subQuerySize==1){     //只涉及一张表的子查询,使用  MiddlerResultHandler 获取中间结果后,改写原有 sql 继续执行 TODO 后期可能会考虑多个子查询的情况.
+				SQLSelect sqlselect = visitor.getSubQuerys().iterator().next();
+				if(!visitor.getRelationships().isEmpty()){     // 当 inner query  和 outer  query  有关联条件时,暂不支持
+					String err = "In case of slice table,sql have different rules,the relationship condition is not supported.";
+					LOGGER.error(err);
+					throw new SQLSyntaxErrorException(err);
+				}else{
+					SQLSelectQuery sqlSelectQuery = sqlselect.getQuery();
+					if(((MySqlSelectQueryBlock)sqlSelectQuery).getFrom() instanceof SQLExprTableSource) {
+						rrs.setCacheAble(false);
+						rrs.setFinishedRoute(true);
+						rrsResult = middlerResultRoute(schema,charset,sqlselect,sqlType,statement,sc);
+					}
+				}
+			}else if(subQuerySize >=2){
+				String err = "In case of slice table,sql has different rules,currently only one subQuery is supported.";
+				LOGGER.error(err);
+				throw new SQLSyntaxErrorException(err);
+			}
+		}
+		return rrsResult;
+	}
+	
+	/**
+	 * 子查询中存在关联查询的情况下,检查关联字段是否是分片字段
+	 * @param rulemap
+	 * @param ships
+	 * @return
+	 */
+	private boolean checkRuleField(Map<String,RuleConfig> rulemap,MycatSchemaStatVisitor visitor){
+		
+		if(!MycatServer.getInstance().getConfig().getSystem().isSubqueryRelationshipCheck()){
+			return true;
+		}
+		
+		Set<Relationship> ships = visitor.getRelationships();
+		Iterator<Relationship> iter = ships.iterator();
+		while(iter.hasNext()){
+			Relationship ship = iter.next();
+			String lefttable = ship.getLeft().getTable().toUpperCase();
+			String righttable = ship.getRight().getTable().toUpperCase();
+			// 如果是同一个表中的关联条件,不做处理
+			if(lefttable.equals(righttable)){
+				return true;
+			}
+			RuleConfig leftconfig = rulemap.get(lefttable);
+			RuleConfig rightconfig = rulemap.get(righttable);
+			
+			if(null!=leftconfig&&null!=rightconfig
+					&&leftconfig.equals(rightconfig)
+					&&leftconfig.getColumn().equals(ship.getLeft().getName().toUpperCase())
+					&&rightconfig.getColumn().equals(ship.getRight().getName().toUpperCase())){
+				return true;
+			}
+		}
+		return false;
+	}
+	
+	private RouteResultset middlerResultRoute(final SchemaConfig schema,final String charset,final SQLSelect sqlselect,
+												final int sqlType,final SQLStatement statement,final ServerConnection sc){
+		
+		final String middlesql = SQLUtils.toMySqlString(sqlselect);
+		
+    	MiddlerResultHandler<String> middlerResultHandler =  new MiddlerQueryResultHandler<>(new SecondHandler() {						 
+				@Override
+				public void doExecute(List param) {
+					sc.getSession2().setMiddlerResultHandler(null);
+					String sqls = null;
+					// 路由计算
+					RouteResultset rrs = null;
+					try {
+						
+						sqls = buildSql(statement,sqlselect,param);
+						rrs = MycatServer
+								.getInstance()
+								.getRouterservice()
+								.route(MycatServer.getInstance().getConfig().getSystem(),
+										schema, sqlType,sqls.toLowerCase(), charset,sc );
+
+					} catch (Exception e) {
+						StringBuilder s = new StringBuilder();
+						LOGGER.warn(s.append(this).append(sqls).toString() + " err:" + e.toString(),e);
+						String msg = e.getMessage();
+						sc.writeErrMessage(ErrorCode.ER_PARSE_ERROR, msg == null ? e.getClass().getSimpleName() : msg);
+						return;
+					}
+					NonBlockingSession noBlockSession =  new NonBlockingSession(sc.getSession2().getSource());
+					noBlockSession.setMiddlerResultHandler(null);
+					//session的预编译标示传递
+					noBlockSession.setPrepared(sc.getSession2().isPrepared());
+					if (rrs != null) {						
+						noBlockSession.setCanClose(false);
+						noBlockSession.execute(rrs, ServerParse.SELECT);
+					}
+				}
+			} );
+    	sc.getSession2().setMiddlerResultHandler(middlerResultHandler);
+    	sc.getSession2().setCanClose(false);
+    
+		// 路由计算
+		RouteResultset rrs = null;
+		try {
+			rrs = MycatServer
+					.getInstance()
+					.getRouterservice()
+					.route(MycatServer.getInstance().getConfig().getSystem(),
+							schema, ServerParse.SELECT, middlesql, charset, sc);
+	
+		} catch (Exception e) {
+			StringBuilder s = new StringBuilder();
+			LOGGER.warn(s.append(this).append(middlesql).toString() + " err:" + e.toString(),e);
+			String msg = e.getMessage();
+			sc.writeErrMessage(ErrorCode.ER_PARSE_ERROR, msg == null ? e.getClass().getSimpleName() : msg);
+			return null;
+		}
+		
+		if(rrs!=null){
+			rrs.setCacheAble(false);
+		}
+		return rrs;
+	}
+	
+	/**
+	 * 获取子查询执行结果后,改写原始sql 继续执行.
+	 * @param statement
+	 * @param sqlselect
+	 * @param param
+	 * @return
+	 */
+	private String buildSql(SQLStatement statement,SQLSelect sqlselect,List param){
+
+		SQLObject parent = sqlselect.getParent();
+		RouteMiddlerReaultHandler handler = middlerResultHandler.get(parent.getClass());
+		if(handler==null){
+			throw new UnsupportedOperationException(parent.getClass()+" current is not supported ");
+		}
+		return handler.dohandler(statement, sqlselect, parent, param);
+	}
+	
+	/**
+	 * 两个表的情况，catlet
+	 * @param schema
+	 * @param stmt
+	 * @param charset
+	 * @param sc
+	 * @return
+	 */
+	private RouteResultset catletRoute(SchemaConfig schema,String stmt,String charset,ServerConnection sc){
+		RouteResultset rrs = null;
+		try {
+			rrs = MycatServer
+					.getInstance()
+					.getRouterservice()
+					.route(MycatServer.getInstance().getConfig().getSystem(),
+							schema, ServerParse.SELECT, "/*!mycat:catlet=io.mycat.catlets.ShareJoin */ "+stmt, charset, sc);
+			
+		}catch(Exception e){
+			
+		}
+		return rrs;
+	}
+	
+	/**
+	 *  直接结果路由
+	 * @param rrs
+	 * @param ctx
+	 * @param schema
+	 * @param druidParser
+	 * @param statement
+	 * @param cachePool
+	 * @return
+	 * @throws SQLNonTransientException
+	 */
+	private RouteResultset directRoute(RouteResultset rrs,DruidShardingParseInfo ctx,SchemaConfig schema,
+										DruidParser druidParser,SQLStatement statement,LayerCachePool cachePool) throws SQLNonTransientException{
+		
+		//改写sql：如insert语句主键自增长, 在直接结果路由的情况下,进行sql 改写处理
+		druidParser.changeSql(schema, rrs, statement,cachePool);
+		
+		/**
+		 * DruidParser 解析过程中已完成了路由的直接返回
+		 */
+		if ( rrs.isFinishedRoute() ) {
+			return rrs;
+		}
+		
+		/**
+		 * 没有from的select语句或其他
+		 */
+        if((ctx.getTables() == null || ctx.getTables().size() == 0)&&(ctx.getTableAliasMap()==null||ctx.getTableAliasMap().isEmpty()))
+        {
+		    return RouterUtil.routeToSingleNode(rrs, schema.getRandomDataNode(), druidParser.getCtx().getSql());
+		}
+
+		if(druidParser.getCtx().getRouteCalculateUnits().size() == 0) {
+			RouteCalculateUnit routeCalculateUnit = new RouteCalculateUnit();
+			druidParser.getCtx().addRouteCalculateUnit(routeCalculateUnit);
+		}
+		
+		SortedSet<RouteResultsetNode> nodeSet = new TreeSet<RouteResultsetNode>();
+		boolean isAllGlobalTable = RouterUtil.isAllGlobalTable(ctx, schema);
+		for(RouteCalculateUnit unit: druidParser.getCtx().getRouteCalculateUnits()) {
+			RouteResultset rrsTmp = RouterUtil.tryRouteForTables(schema, druidParser.getCtx(), unit, rrs, isSelect(statement), cachePool);
+			if(rrsTmp != null&&rrsTmp.getNodes()!=null) {
+				for(RouteResultsetNode node :rrsTmp.getNodes()) {
+					nodeSet.add(node);
+				}
+			}
+			if(isAllGlobalTable) {//都是全局表时只计算一遍路由
+				break;
+			}
+		}
+		
+		RouteResultsetNode[] nodes = new RouteResultsetNode[nodeSet.size()];
+		int i = 0;
+		for (RouteResultsetNode aNodeSet : nodeSet) {
+			nodes[i] = aNodeSet;
+			  if(statement instanceof MySqlInsertStatement &&ctx.getTables().size()==1&&schema.getTables().containsKey(ctx.getTables().get(0))) {
+				  RuleConfig rule = schema.getTables().get(ctx.getTables().get(0)).getRule();
+				  if(rule!=null&&  rule.getRuleAlgorithm() instanceof SlotFunction){
+					 aNodeSet.setStatement(ParseUtil.changeInsertAddSlot(aNodeSet.getStatement(),aNodeSet.getSlot()));
+				  }
+			  }
+			i++;
+		}		
+		rrs.setNodes(nodes);		
+		
+		//分表
+		/**
+		 *  subTables="t_order$1-2,t_order3"
+		 *目前分表 1.6 开始支持 幵丏 dataNode 在分表条件下只能配置一个，分表条件下不支持join。
+		 */
+		if(rrs.isDistTable()){
+			return this.routeDisTable(statement,rrs);
+		}
+		return rrs;
+	}
+	
+	private SQLExprTableSource getDisTable(SQLTableSource tableSource,RouteResultsetNode node) throws SQLSyntaxErrorException{
+		if(node.getSubTableName()==null){
+			String msg = " sub table not exists for " + node.getName() + " on " + tableSource;
+			LOGGER.error("DruidMycatRouteStrategyError " + msg);
+			throw new SQLSyntaxErrorException(msg);
+		}
+		
+		SQLIdentifierExpr sqlIdentifierExpr = new SQLIdentifierExpr();
+		sqlIdentifierExpr.setParent(tableSource.getParent());
+		sqlIdentifierExpr.setName(node.getSubTableName());
+		SQLExprTableSource from2 = new SQLExprTableSource(sqlIdentifierExpr);
+		return from2;
+	}
+	
+	private RouteResultset routeDisTable(SQLStatement statement, RouteResultset rrs) throws SQLSyntaxErrorException{
+		SQLTableSource tableSource = null;
+		if(statement instanceof SQLInsertStatement) {
+			SQLInsertStatement insertStatement = (SQLInsertStatement) statement;
+			tableSource = insertStatement.getTableSource();
+			for (RouteResultsetNode node : rrs.getNodes()) {
+				SQLExprTableSource from2 = getDisTable(tableSource, node);
+				insertStatement.setTableSource(from2);
+				node.setStatement(insertStatement.toString());
+	        }
+		}
+		if(statement instanceof SQLDeleteStatement) {
+			SQLDeleteStatement deleteStatement = (SQLDeleteStatement) statement;
+			tableSource = deleteStatement.getTableSource();
+			SQLTableSource from = deleteStatement.getFrom();
+			for (RouteResultsetNode node : rrs.getNodes()) {
+				SQLExprTableSource from2 = getDisTable(tableSource, node);
+				
+				if (from == null) {
+					from2.setAlias(tableSource.toString());
+					deleteStatement.setFrom(from2);
+				} else {
+					String alias = from.getAlias();
+					from2.setAlias(alias);
+					deleteStatement.setFrom(from2);
+				}
+				
+				node.setStatement(deleteStatement.toString());
+	        }
+		}
+		if(statement instanceof SQLUpdateStatement) {
+			SQLUpdateStatement updateStatement = (SQLUpdateStatement) statement;
+			tableSource = updateStatement.getTableSource();
+			for (RouteResultsetNode node : rrs.getNodes()) {
+				SQLExprTableSource from2 = getDisTable(tableSource, node);
+				from2.setAlias(updateStatement.getTableSource().getAlias());
+				updateStatement.setTableSource(from2);
+				node.setStatement(updateStatement.toString());
+	        }
+		}
+		
+		return rrs;
+	}
+
+	/**
+	 * SELECT 语句
+	 */
+    private boolean isSelect(SQLStatement statement) {
+		if(statement instanceof SQLSelectStatement) {
+			return true;
+		}
+		return false;
+	}
+	
+	/**
+	 * 检验不支持的SQLStatement类型 ：不支持的类型直接抛SQLSyntaxErrorException异常
+	 * @param statement
+	 * @throws SQLSyntaxErrorException
+	 */
+	private void checkUnSupportedStatement(SQLStatement statement) throws SQLSyntaxErrorException {
+		//不支持replace语句
+		if(statement instanceof MySqlReplaceStatement) {
+			throw new SQLSyntaxErrorException(" ReplaceStatement can't be supported,use insert into ...on duplicate key update... instead ");
+		}
+	}
+	
+	/**
+	 * 分析 SHOW SQL
+	 */
+	@Override
+	public RouteResultset analyseShowSQL(SchemaConfig schema,
+			RouteResultset rrs, String stmt) throws SQLSyntaxErrorException {
+		
+		String upStmt = stmt.toUpperCase();
+		int tabInd = upStmt.indexOf(" TABLES");
+		if (tabInd > 0) {// show tables
+			int[] nextPost = RouterUtil.getSpecPos(upStmt, 0);
+			if (nextPost[0] > 0) {// remove db info
+				int end = RouterUtil.getSpecEndPos(upStmt, tabInd);
+				if (upStmt.indexOf(" FULL") > 0) {
+					stmt = "SHOW FULL TABLES" + stmt.substring(end);
+				} else {
+					stmt = "SHOW TABLES" + stmt.substring(end);
+				}
+			}
+          String defaultNode=  schema.getDataNode();
+            if(!Strings.isNullOrEmpty(defaultNode))
+            {
+             return    RouterUtil.routeToSingleNode(rrs, defaultNode, stmt);
+            }
+			return RouterUtil.routeToMultiNode(false, rrs, schema.getMetaDataNodes(), stmt);
+		}
+		
+		/**
+		 *  show index or column
+		 */
+		int[] indx = RouterUtil.getSpecPos(upStmt, 0);
+		if (indx[0] > 0) {
+			/**
+			 *  has table
+			 */
+			int[] repPos = { indx[0] + indx[1], 0 };
+			String tableName = RouterUtil.getShowTableName(stmt, repPos);
+			/**
+			 *  IN DB pattern
+			 */
+			int[] indx2 = RouterUtil.getSpecPos(upStmt, indx[0] + indx[1] + 1);
+			if (indx2[0] > 0) {// find LIKE OR WHERE
+				repPos[1] = RouterUtil.getSpecEndPos(upStmt, indx2[0] + indx2[1]);
+
+			}
+			stmt = stmt.substring(0, indx[0]) + " FROM " + tableName + stmt.substring(repPos[1]);
+			RouterUtil.routeForTableMeta(rrs, schema, tableName, stmt);
+			return rrs;
+
+		}
+		
+		/**
+		 *  show create table tableName
+		 */
+		int[] createTabInd = RouterUtil.getCreateTablePos(upStmt, 0);
+		if (createTabInd[0] > 0) {
+			int tableNameIndex = createTabInd[0] + createTabInd[1];
+			if (upStmt.length() > tableNameIndex) {
+				String tableName = stmt.substring(tableNameIndex).trim();
+				int ind2 = tableName.indexOf('.');
+				if (ind2 > 0) {
+					tableName = tableName.substring(ind2 + 1);
+				}
+				RouterUtil.routeForTableMeta(rrs, schema, tableName, stmt);
+				return rrs;
+			}
+		}
+
+		return RouterUtil.routeToSingleNode(rrs, schema.getRandomDataNode(), stmt);
+	}
+	
+	
+//	/**
+//	 * 为一个表进行条件路由
+//	 * @param schema
+//	 * @param tablesAndConditions
+//	 * @param tablesRouteMap
+//	 * @throws SQLNonTransientException
+//	 */
+//	private static RouteResultset findRouteWithcConditionsForOneTable(SchemaConfig schema, RouteResultset rrs,
+//		Map<String, Set<ColumnRoutePair>> conditions, String tableName, String sql) throws SQLNonTransientException {
+//		boolean cache = rrs.isCacheAble();
+//	    //为分库表找路由
+//		tableName = tableName.toUpperCase();
+//		TableConfig tableConfig = schema.getTables().get(tableName);
+//		//全局表或者不分库的表略过（全局表后面再计算）
+//		if(tableConfig.isGlobalTable()) {
+//			return null;
+//		} else {//非全局表
+//			Set<String> routeSet = new HashSet<String>();
+//			String joinKey = tableConfig.getJoinKey();
+//			for(Map.Entry<String, Set<ColumnRoutePair>> condition : conditions.entrySet()) {
+//				String colName = condition.getKey();
+//				//条件字段是拆分字段
+//				if(colName.equals(tableConfig.getPartitionColumn())) {
+//					Set<ColumnRoutePair> columnPairs = condition.getValue();
+//					
+//					for(ColumnRoutePair pair : columnPairs) {
+//						if(pair.colValue != null) {
+//							Integer nodeIndex = tableConfig.getRule().getRuleAlgorithm().calculate(pair.colValue);
+//							if(nodeIndex == null) {
+//								String msg = "can't find any valid datanode :" + tableConfig.getName() 
+//										+ " -> " + tableConfig.getPartitionColumn() + " -> " + pair.colValue;
+//								LOGGER.warn(msg);
+//								throw new SQLNonTransientException(msg);
+//							}
+//							String node = tableConfig.getDataNodes().get(nodeIndex);
+//							if(node != null) {//找到一个路由节点
+//								routeSet.add(node);
+//							}
+//						}
+//						if(pair.rangeValue != null) {
+//							Integer[] nodeIndexs = tableConfig.getRule().getRuleAlgorithm()
+//									.calculateRange(pair.rangeValue.beginValue.toString(), pair.rangeValue.endValue.toString());
+//							for(Integer idx : nodeIndexs) {
+//								String node = tableConfig.getDataNodes().get(idx);
+//								if(node != null) {//找到一个路由节点
+//									routeSet.add(node);
+//								}
+//							}
+//						}
+//					}
+//				} else if(joinKey != null && joinKey.equals(colName)) {
+//					Set<String> dataNodeSet = RouterUtil.ruleCalculate(
+//							tableConfig.getParentTC(), condition.getValue());
+//					if (dataNodeSet.isEmpty()) {
+//						throw new SQLNonTransientException(
+//								"parent key can't find any valid datanode ");
+//					}
+//					if (LOGGER.isDebugEnabled()) {
+//						LOGGER.debug("found partion nodes (using parent partion rule directly) for child table to update  "
+//								+ Arrays.toString(dataNodeSet.toArray()) + " sql :" + sql);
+//					}
+//					if (dataNodeSet.size() > 1) {
+//						return RouterUtil.routeToMultiNode(rrs.isCacheAble(), rrs, schema.getAllDataNodes(), sql);
+//					} else {
+//						rrs.setCacheAble(true);
+//						return RouterUtil.routeToSingleNode(rrs, dataNodeSet.iterator().next(), sql);
+//					}
+//				} else {//条件字段不是拆分字段也不是join字段,略过
+//					continue;
+//					
+//				}
+//			}
+//			return RouterUtil.routeToMultiNode(cache, rrs, routeSet, sql);
+//			
+//		}
+//
+//	}
+
+	public RouteResultset routeSystemInfo(SchemaConfig schema, int sqlType,
+			String stmt, RouteResultset rrs) throws SQLSyntaxErrorException {
+		switch(sqlType){
+		case ServerParse.SHOW:// if origSQL is like show tables
+			return analyseShowSQL(schema, rrs, stmt);
+		case ServerParse.SELECT://if origSQL is like select @@
+			int index = stmt.indexOf("@@");
+			if(index > 0 && "SELECT".equals(stmt.substring(0, index).trim().toUpperCase())){
+				return analyseDoubleAtSgin(schema, rrs, stmt);
+			}
+			break;
+		case ServerParse.DESCRIBE:// if origSQL is meta SQL, such as describe table
+			int ind = stmt.indexOf(' ');
+			stmt = stmt.trim();
+			return analyseDescrSQL(schema, rrs, stmt, ind + 1);
+		}
+		return null;
+	}
+	
+	/**
+	 * 对Desc语句进行分析 返回数据路由集合
+	 * 	 * 
+	 * @param schema   				数据库名
+	 * @param rrs    				数据路由集合
+	 * @param stmt   				执行语句
+	 * @param ind    				第一个' '的位置
+	 * @return RouteResultset		(数据路由集合)
+	 * @author mycat
+	 */
+	private static RouteResultset analyseDescrSQL(SchemaConfig schema,
+			RouteResultset rrs, String stmt, int ind) {
+		
+		final String MATCHED_FEATURE = "DESCRIBE ";
+		final String MATCHED2_FEATURE = "DESC ";
+		int pos = 0;
+		while (pos < stmt.length()) {
+			char ch = stmt.charAt(pos);
+			// 忽略处理注释 /* */ BEN
+			if(ch == '/' &&  pos+4 < stmt.length() && stmt.charAt(pos+1) == '*') {
+				if(stmt.substring(pos+2).indexOf("*/") != -1) {
+					pos += stmt.substring(pos+2).indexOf("*/")+4;
+					continue;
+				} else {
+					// 不应该发生这类情况。
+					throw new IllegalArgumentException("sql 注释 语法错误");
+				}
+			} else if(ch == 'D'||ch == 'd') {
+				// 匹配 [describe ] 
+				if(pos+MATCHED_FEATURE.length() < stmt.length() && (stmt.substring(pos).toUpperCase().indexOf(MATCHED_FEATURE) != -1)) {
+					pos = pos + MATCHED_FEATURE.length();
+					break;
+				} else if(pos+MATCHED2_FEATURE.length() < stmt.length() && (stmt.substring(pos).toUpperCase().indexOf(MATCHED2_FEATURE) != -1)) {
+					pos = pos + MATCHED2_FEATURE.length();
+					break;
+				} else {
+					pos++;
+				}
+			}
+		}
+		
+		// 重置ind坐标。BEN GONG
+		ind = pos;		
+		int[] repPos = { ind, 0 };
+		String tableName = RouterUtil.getTableName(stmt, repPos);
+		
+		stmt = stmt.substring(0, ind) + tableName + stmt.substring(repPos[1]);
+		RouterUtil.routeForTableMeta(rrs, schema, tableName, stmt);
+		return rrs;
+	}
+	
+	/**
+	 * 根据执行语句判断数据路由
+	 * 
+	 * @param schema     			数据库名
+	 * @param rrs		  		 	数据路由集合
+	 * @param stmt		  	 		执行sql
+	 * @return RouteResultset		数据路由集合
+	 * @throws SQLSyntaxErrorException
+	 * @author mycat
+	 */
+	private RouteResultset analyseDoubleAtSgin(SchemaConfig schema,
+			RouteResultset rrs, String stmt) throws SQLSyntaxErrorException {		
+		String upStmt = stmt.toUpperCase();
+		int atSginInd = upStmt.indexOf(" @@");
+		if (atSginInd > 0) {
+			return RouterUtil.routeToMultiNode(false, rrs, schema.getMetaDataNodes(), stmt);
+		}
+		return RouterUtil.routeToSingleNode(rrs, schema.getRandomDataNode(), stmt);
+	}
 }
\ No newline at end of file
diff --git a/src/main/java/io/mycat/route/parser/druid/impl/DruidSelectParser.java b/src/main/java/io/mycat/route/parser/druid/impl/DruidSelectParser.java
index 66770a8db..846939051 100644
--- a/src/main/java/io/mycat/route/parser/druid/impl/DruidSelectParser.java
+++ b/src/main/java/io/mycat/route/parser/druid/impl/DruidSelectParser.java
@@ -1,764 +1,812 @@
-package io.mycat.route.parser.druid.impl;
-
-import java.sql.SQLNonTransientException;
-import java.util.ArrayList;
-import java.util.Collection;
-import java.util.HashMap;
-import java.util.Iterator;
-import java.util.LinkedHashMap;
-import java.util.List;
-import java.util.Map;
-import java.util.Set;
-import java.util.SortedSet;
-import java.util.TreeSet;
-
-import com.alibaba.druid.sql.SQLUtils;
-import com.alibaba.druid.sql.ast.SQLExpr;
-import com.alibaba.druid.sql.ast.SQLName;
-import com.alibaba.druid.sql.ast.SQLOrderingSpecification;
-import com.alibaba.druid.sql.ast.SQLStatement;
-import com.alibaba.druid.sql.ast.expr.SQLAggregateExpr;
-import com.alibaba.druid.sql.ast.expr.SQLAllColumnExpr;
-import com.alibaba.druid.sql.ast.expr.SQLBinaryOpExpr;
-import com.alibaba.druid.sql.ast.expr.SQLBinaryOperator;
-import com.alibaba.druid.sql.ast.expr.SQLIdentifierExpr;
-import com.alibaba.druid.sql.ast.expr.SQLIntegerExpr;
-import com.alibaba.druid.sql.ast.expr.SQLMethodInvokeExpr;
-import com.alibaba.druid.sql.ast.expr.SQLNumericLiteralExpr;
-import com.alibaba.druid.sql.ast.expr.SQLPropertyExpr;
-import com.alibaba.druid.sql.ast.expr.SQLTextLiteralExpr;
-import com.alibaba.druid.sql.ast.statement.SQLExprTableSource;
-import com.alibaba.druid.sql.ast.statement.SQLSelectGroupByClause;
-import com.alibaba.druid.sql.ast.statement.SQLSelectItem;
-import com.alibaba.druid.sql.ast.statement.SQLSelectOrderByItem;
-import com.alibaba.druid.sql.ast.statement.SQLSelectQuery;
-import com.alibaba.druid.sql.ast.statement.SQLSelectQueryBlock;
-import com.alibaba.druid.sql.ast.statement.SQLSelectStatement;
-import com.alibaba.druid.sql.ast.statement.SQLTableSource;
-import com.alibaba.druid.sql.dialect.db2.ast.stmt.DB2SelectQueryBlock;
-import com.alibaba.druid.sql.dialect.db2.visitor.DB2OutputVisitor;
-import com.alibaba.druid.sql.dialect.mysql.ast.expr.MySqlOrderingExpr;
-import com.alibaba.druid.sql.dialect.mysql.ast.statement.MySqlSelectQueryBlock;
-import com.alibaba.druid.sql.dialect.mysql.ast.statement.MySqlSelectQueryBlock.Limit;
-import com.alibaba.druid.sql.dialect.mysql.ast.statement.MySqlUnionQuery;
-import com.alibaba.druid.sql.dialect.mysql.visitor.MySqlOutputVisitor;
-import com.alibaba.druid.sql.dialect.mysql.visitor.MySqlSchemaStatVisitor;
-import com.alibaba.druid.sql.dialect.oracle.ast.stmt.OracleSelectQueryBlock;
-import com.alibaba.druid.sql.dialect.oracle.visitor.OracleOutputVisitor;
-import com.alibaba.druid.sql.dialect.postgresql.ast.stmt.PGSelectQueryBlock;
-import com.alibaba.druid.sql.dialect.postgresql.visitor.PGOutputVisitor;
-import com.alibaba.druid.sql.dialect.sqlserver.ast.SQLServerSelectQueryBlock;
-import com.alibaba.druid.sql.visitor.SQLASTOutputVisitor;
-import com.alibaba.druid.util.JdbcConstants;
-import com.alibaba.druid.wall.spi.WallVisitorUtils;
-
-import io.mycat.MycatServer;
-import io.mycat.cache.LayerCachePool;
-import io.mycat.config.ErrorCode;
-import io.mycat.config.model.SchemaConfig;
-import io.mycat.config.model.TableConfig;
-import io.mycat.route.RouteResultset;
-import io.mycat.route.RouteResultsetNode;
-import io.mycat.route.parser.druid.MycatSchemaStatVisitor;
-import io.mycat.route.parser.druid.RouteCalculateUnit;
-import io.mycat.route.util.RouterUtil;
-import io.mycat.sqlengine.mpp.ColumnRoutePair;
-import io.mycat.sqlengine.mpp.HavingCols;
-import io.mycat.sqlengine.mpp.MergeCol;
-import io.mycat.sqlengine.mpp.OrderCol;
-import io.mycat.util.ObjectUtil;
-import io.mycat.util.StringUtil;
-
-public class DruidSelectParser extends DefaultDruidParser {
-
-
-    protected boolean isNeedParseOrderAgg=true;
-
-    @Override
-	public void statementParse(SchemaConfig schema, RouteResultset rrs, SQLStatement stmt) {
-		SQLSelectStatement selectStmt = (SQLSelectStatement)stmt;
-		SQLSelectQuery sqlSelectQuery = selectStmt.getSelect().getQuery();
-		if(sqlSelectQuery instanceof MySqlSelectQueryBlock) {
-			MySqlSelectQueryBlock mysqlSelectQuery = (MySqlSelectQueryBlock)selectStmt.getSelect().getQuery();
-
-				 parseOrderAggGroupMysql(schema, stmt,rrs, mysqlSelectQuery);
-				 //更改canRunInReadDB属性
-				 if ((mysqlSelectQuery.isForUpdate() || mysqlSelectQuery.isLockInShareMode()) && rrs.isAutocommit() == false)
-				 {
-					 rrs.setCanRunInReadDB(false);
-				 }
-
-		} else if (sqlSelectQuery instanceof MySqlUnionQuery) { 
-//			MySqlUnionQuery unionQuery = (MySqlUnionQuery)sqlSelectQuery;
-//			MySqlSelectQueryBlock left = (MySqlSelectQueryBlock)unionQuery.getLeft();
-//			MySqlSelectQueryBlock right = (MySqlSelectQueryBlock)unionQuery.getLeft();
-//			System.out.println();
-		}
-	}
-	protected void parseOrderAggGroupMysql(SchemaConfig schema, SQLStatement stmt, RouteResultset rrs, MySqlSelectQueryBlock mysqlSelectQuery)
-	{
-		MySqlSchemaStatVisitor visitor = new MySqlSchemaStatVisitor();
-		stmt.accept(visitor);
-//		rrs.setGroupByCols((String[])visitor.getGroupByColumns().toArray());
-		if(!isNeedParseOrderAgg)
-        {
-            return;
-        }
-		Map<String, String> aliaColumns = parseAggGroupCommon(schema, stmt, rrs, mysqlSelectQuery);
-
-		//setOrderByCols
-		if(mysqlSelectQuery.getOrderBy() != null) {
-			List<SQLSelectOrderByItem> orderByItems = mysqlSelectQuery.getOrderBy().getItems();
-			rrs.setOrderByCols(buildOrderByCols(orderByItems,aliaColumns));
-		}
-        isNeedParseOrderAgg=false;
-	}
-	protected Map<String, String> parseAggGroupCommon(SchemaConfig schema, SQLStatement stmt, RouteResultset rrs, SQLSelectQueryBlock mysqlSelectQuery)
-	{
-		Map<String, String> aliaColumns = new HashMap<String, String>();
-		Map<String, Integer> aggrColumns = new HashMap<String, Integer>();
-		// Added by winbill, 20160314, for having clause, Begin ==>
-		List<String> havingColsName = new ArrayList<String>();
-		// Added by winbill, 20160314, for having clause, End  <==
-		List<SQLSelectItem> selectList = mysqlSelectQuery.getSelectList();
-        boolean isNeedChangeSql=false;
-        int size = selectList.size();
-        boolean isDistinct=mysqlSelectQuery.getDistionOption()==2;
-        for (int i = 0; i < size; i++)
-		{
-			SQLSelectItem item = selectList.get(i);
-
-			if (item.getExpr() instanceof SQLAggregateExpr)
-			{
-				SQLAggregateExpr expr = (SQLAggregateExpr) item.getExpr();
-				String method = expr.getMethodName();
-                boolean isHasArgument=!expr.getArguments().isEmpty();
-                if(isHasArgument)
-                {
-                    String aggrColName = method + "(" + expr.getArguments().get(0) + ")";   // Added by winbill, 20160314, for having clause
-                    havingColsName.add(aggrColName);       // Added by winbill, 20160314, for having clause
-                }
-				//只处理有别名的情况，无别名添加别名，否则某些数据库会得不到正确结果处理
-				int mergeType = MergeCol.getMergeType(method);
-                if (MergeCol.MERGE_AVG == mergeType&&isRoutMultiNode(schema,rrs))
-                {    //跨分片avg需要特殊处理，直接avg结果是不对的
-                    String colName = item.getAlias() != null ? item.getAlias() : method + i;
-                    SQLSelectItem sum =new SQLSelectItem();
-                    String sumColName = colName + "SUM";
-                    sum.setAlias(sumColName);
-                    SQLAggregateExpr sumExp =new SQLAggregateExpr("SUM");
-                    ObjectUtil.copyProperties(expr,sumExp);
-                    sumExp.getArguments().addAll(expr.getArguments());
-                    sumExp.setMethodName("SUM");
-                    sum.setExpr(sumExp);
-                    selectList.set(i, sum);
-                    aggrColumns.put(sumColName, MergeCol.MERGE_SUM);
-                    havingColsName.add(sumColName);    // Added by winbill, 20160314, for having clause
-                    havingColsName.add(item.getAlias() != null ? item.getAlias() : "");    // Added by winbill, 20160314, two aliases for AVG
-
-                    SQLSelectItem count =new SQLSelectItem();
-                    String countColName = colName + "COUNT";
-                    count.setAlias(countColName);
-                    SQLAggregateExpr countExp = new SQLAggregateExpr("COUNT");
-                    ObjectUtil.copyProperties(expr,countExp);
-                    countExp.getArguments().addAll(expr.getArguments());
-                    countExp.setMethodName("COUNT");
-                    count.setExpr(countExp);
-                    selectList.add(count);
-                    aggrColumns.put(countColName, MergeCol.MERGE_COUNT);
-
-                    isNeedChangeSql=true;
-                    aggrColumns.put(colName, mergeType);
-                    rrs.setHasAggrColumn(true);
-                } else if (MergeCol.MERGE_UNSUPPORT != mergeType){
-					String aggColName = null;
-					StringBuilder sb = new StringBuilder();
-					if(mysqlSelectQuery instanceof MySqlSelectQueryBlock) {
-						expr.accept(new MySqlOutputVisitor(sb));
-					} else if(mysqlSelectQuery instanceof OracleSelectQueryBlock) {
-						expr.accept(new OracleOutputVisitor(sb));
-					} else if(mysqlSelectQuery instanceof PGSelectQueryBlock){
-						expr.accept(new PGOutputVisitor(sb));
-					} else if(mysqlSelectQuery instanceof SQLServerSelectQueryBlock) {
-						expr.accept(new SQLASTOutputVisitor(sb));
-					} else if(mysqlSelectQuery instanceof DB2SelectQueryBlock) {
-						expr.accept(new DB2OutputVisitor(sb));
-					}
-					aggColName = sb.toString();
-
-					if (item.getAlias() != null && item.getAlias().length() > 0)
-					{
-						aggrColumns.put(item.getAlias(), mergeType);
-						aliaColumns.put(aggColName,item.getAlias());
-					} else
-					{   //如果不加，jdbc方式时取不到正确结果   ;修改添加别名
-							item.setAlias(method + i);
-							aggrColumns.put(method + i, mergeType);
-							aliaColumns.put(aggColName, method + i);
-                            isNeedChangeSql=true;
-					}
-					rrs.setHasAggrColumn(true);
-					havingColsName.add(item.getAlias());   // Added by winbill, 20160314, for having clause
-					havingColsName.add("");                // Added by winbill, 20160314, one alias for non-AVG
-				}
-			} else
-			{
-				if (!(item.getExpr() instanceof SQLAllColumnExpr))
-				{
-					String alia = item.getAlias();
-					String field = getFieldName(item);
-					if (alia == null)
-					{
-						alia = field;
-					}
-					aliaColumns.put(field, alia);
-				}
-			}
-
-		}
-		if(aggrColumns.size() > 0) {
-			rrs.setMergeCols(aggrColumns);
-		}
-
-        //通过优化转换成group by来实现
-        if(isDistinct)
-        {
-            mysqlSelectQuery.setDistionOption(0);
-            SQLSelectGroupByClause   groupBy=new SQLSelectGroupByClause();
-            for (String fieldName : aliaColumns.keySet())
-            {
-                groupBy.addItem(new SQLIdentifierExpr(fieldName));
-            }
-            mysqlSelectQuery.setGroupBy(groupBy);
-            isNeedChangeSql=true;
-        }
-
-
-        //setGroupByCols
-		if(mysqlSelectQuery.getGroupBy() != null) {
-			List<SQLExpr> groupByItems = mysqlSelectQuery.getGroupBy().getItems();
-			String[] groupByCols = buildGroupByCols(groupByItems,aliaColumns);
-			rrs.setGroupByCols(groupByCols);
-			rrs.setHavings(buildGroupByHaving(mysqlSelectQuery.getGroupBy().getHaving(),aliaColumns));
-			rrs.setHasAggrColumn(true);
-			rrs.setHavingColsName(havingColsName.toArray()); // Added by winbill, 20160314, for having clause
-		}
-
-
-        if (isNeedChangeSql)
-        {
-            String sql = stmt.toString();
-            rrs.changeNodeSqlAfterAddLimit(schema,getCurentDbType(),sql,0,-1, false);
-            getCtx().setSql(sql);
-        }
-		return aliaColumns;
-	}
-
-	private HavingCols buildGroupByHaving(SQLExpr having,Map<String, String> aliaColumns ){
-		if (having == null) {
-			return null;
-		}
-
-		SQLBinaryOpExpr expr  = ((SQLBinaryOpExpr) having);
-		SQLExpr left = expr.getLeft();
-		SQLBinaryOperator operator = expr.getOperator();
-		SQLExpr right = expr.getRight();
-
-		String leftValue = null;;
-		if (left instanceof SQLAggregateExpr) {
-			leftValue = ((SQLAggregateExpr) left).getMethodName() + "("
-					+ ((SQLAggregateExpr) left).getArguments().get(0) + ")";
-			String aggrColumnAlias = getAliaColumn(aliaColumns,leftValue);
-			if(aggrColumnAlias != null) { // having聚合函数存在别名
-				expr.setLeft(new SQLIdentifierExpr(aggrColumnAlias));
-				leftValue = aggrColumnAlias;
-			}
-		} else if (left instanceof SQLIdentifierExpr) {
-			leftValue = ((SQLIdentifierExpr) left).getName();
-		}
-
-		String rightValue = null;
-		if (right instanceof  SQLNumericLiteralExpr) {
-			rightValue = right.toString();
-		}else if(right instanceof SQLTextLiteralExpr){
-			rightValue = StringUtil.removeBackquote(right.toString());
-		}
-
-		return new HavingCols(leftValue,rightValue,operator.getName());
-	}
-
-  private boolean isRoutMultiNode(SchemaConfig schema,  RouteResultset rrs)
-  {
-	  if(rrs.getNodes()!=null&&rrs.getNodes().length>1)
-	  {
-		  return true;
-	  }
-	  LayerCachePool tableId2DataNodeCache = (LayerCachePool) MycatServer.getInstance().getCacheService().getCachePool("TableID2DataNodeCache");
-	  try
-	  {
-		  tryRoute(schema, rrs, tableId2DataNodeCache);
-		  if(rrs.getNodes()!=null&&rrs.getNodes().length>1)
-		  {
-			  return true;
-		  }
-	  } catch (SQLNonTransientException e)
-	  {
-		  throw new RuntimeException(e);
-	  }
-	  return false;
-  }
-
-	private String getFieldName(SQLSelectItem item){
-		if ((item.getExpr() instanceof SQLPropertyExpr)||(item.getExpr() instanceof SQLMethodInvokeExpr)
-				|| (item.getExpr() instanceof SQLIdentifierExpr) || item.getExpr() instanceof SQLBinaryOpExpr) {			
-			return item.getExpr().toString();//字段别名
-		}
-		else {
-			return item.toString();
-		}
-	}
-	
-	/**
-	 * 现阶段目标为 有一个只涉及到一张表的子查询时,先执行子查询,获得返回结果后,改写原有sql继续执行,得到最终结果.
-	 * 在这种情况下,原sql不需要继续解析.
-	 * 使用catlet 的情况也不再继续解析.
-	 */
-	@Override
-	public boolean afterVisitorParser(RouteResultset rrs, SQLStatement stmt, MycatSchemaStatVisitor visitor) {
-		int subQuerySize = visitor.getSubQuerys().size();
-		
-		if(subQuerySize==0&&ctx.getTables().size()==2){ //两表关联,考虑使用catlet
-		    if(ctx.getVisitor().getConditions() !=null && ctx.getVisitor().getConditions().size()>0){
-		    	return true;
-			}
-		}else if(subQuerySize==1){     //只涉及一张表的子查询,使用  MiddlerResultHandler 获取中间结果后,改写原有 sql 继续执行 TODO 后期可能会考虑多个.
-			SQLSelectQuery sqlSelectQuery = visitor.getSubQuerys().iterator().next().getQuery();
-			if(((MySqlSelectQueryBlock)sqlSelectQuery).getFrom() instanceof SQLExprTableSource) {
-				return true;
-			}
-		}
-		
-		return super.afterVisitorParser(rrs, stmt, visitor);
-	}
-	
-	/**
-	 * 改写sql：需要加limit的加上
-	 */
-	@Override
-	public void changeSql(SchemaConfig schema, RouteResultset rrs, SQLStatement stmt,LayerCachePool cachePool) throws SQLNonTransientException {
-
-		tryRoute(schema, rrs, cachePool);
-
-		rrs.copyLimitToNodes();
-		
-		SQLSelectStatement selectStmt = (SQLSelectStatement)stmt;
-		SQLSelectQuery sqlSelectQuery = selectStmt.getSelect().getQuery();
-		if(sqlSelectQuery instanceof MySqlSelectQueryBlock) {
-			MySqlSelectQueryBlock mysqlSelectQuery = (MySqlSelectQueryBlock)selectStmt.getSelect().getQuery();
-			int limitStart = 0;
-			int limitSize = schema.getDefaultMaxLimit();
-
-			//clear group having
-			SQLSelectGroupByClause groupByClause = mysqlSelectQuery.getGroupBy();
-			// Modified by winbill, 20160614, do NOT include having clause when routing to multiple nodes
-			if(groupByClause != null && groupByClause.getHaving() != null && isRoutMultiNode(schema,rrs)){
-				groupByClause.setHaving(null);
-			}
-			
-			Map<String, Map<String, Set<ColumnRoutePair>>> allConditions = getAllConditions();
-			boolean isNeedAddLimit = isNeedAddLimit(schema, rrs, mysqlSelectQuery, allConditions);
-			if(isNeedAddLimit) {
-				Limit limit = new Limit();
-				limit.setRowCount(new SQLIntegerExpr(limitSize));
-				mysqlSelectQuery.setLimit(limit);
-				rrs.setLimitSize(limitSize);
-			    String sql= getSql(rrs, stmt, isNeedAddLimit);
-				rrs.changeNodeSqlAfterAddLimit(schema, getCurentDbType(), sql, 0, limitSize, true);
-
-			}
-			Limit limit = mysqlSelectQuery.getLimit();
-			if(limit != null&&!isNeedAddLimit) {
-				SQLIntegerExpr offset = (SQLIntegerExpr)limit.getOffset();
-				SQLIntegerExpr count = (SQLIntegerExpr)limit.getRowCount();
-				if(offset != null) {
-					limitStart = offset.getNumber().intValue();
-					rrs.setLimitStart(limitStart);
-				} 
-				if(count != null) {
-					limitSize = count.getNumber().intValue();
-					rrs.setLimitSize(limitSize);
-				}
-
-				if(isNeedChangeLimit(rrs)) {
-					Limit changedLimit = new Limit();
-					changedLimit.setRowCount(new SQLIntegerExpr(limitStart + limitSize));
-					
-					if(offset != null) {
-						if(limitStart < 0) {
-							String msg = "You have an error in your SQL syntax; check the manual that " +
-									"corresponds to your MySQL server version for the right syntax to use near '" + limitStart + "'";
-							throw new SQLNonTransientException(ErrorCode.ER_PARSE_ERROR + " - " + msg);
-						} else {
-							changedLimit.setOffset(new SQLIntegerExpr(0));
-							
-						}
-					}
-					
-					mysqlSelectQuery.setLimit(changedLimit);
-
-                    String sql= getSql(rrs, stmt, isNeedAddLimit);
-					rrs.changeNodeSqlAfterAddLimit(schema,getCurentDbType(),sql,0, limitStart + limitSize, true);
-
-					//设置改写后的sql
-					ctx.setSql(sql);
-
-				}   else
-				{
-
-                        rrs.changeNodeSqlAfterAddLimit(schema,getCurentDbType(),getCtx().getSql(),rrs.getLimitStart(), rrs.getLimitSize(), true);
-					//	ctx.setSql(nativeSql);
-
-				}
-				
-
-			}
-			
-			if(rrs.isDistTable()){
-				SQLTableSource from = mysqlSelectQuery.getFrom();
-
-				for (RouteResultsetNode node : rrs.getNodes()) {
-					SQLIdentifierExpr sqlIdentifierExpr = new SQLIdentifierExpr();
-					sqlIdentifierExpr.setParent(from);
-					sqlIdentifierExpr.setName(node.getSubTableName());
-					SQLExprTableSource from2 = new SQLExprTableSource(sqlIdentifierExpr);
-					from2.setAlias(from.getAlias());
-					mysqlSelectQuery.setFrom(from2);
-					node.setStatement(stmt.toString());
-	            }
-			}
-			
-			rrs.setCacheAble(isNeedCache(schema, rrs, mysqlSelectQuery, allConditions));
-		}
-		
-	}
-	
-	/**
-	 * 获取所有的条件：因为可能被or语句拆分成多个RouteCalculateUnit，条件分散了
-	 * @return
-	 */
-	private Map<String, Map<String, Set<ColumnRoutePair>>> getAllConditions() {
-		Map<String, Map<String, Set<ColumnRoutePair>>> map = new HashMap<String, Map<String, Set<ColumnRoutePair>>>();
-		for(RouteCalculateUnit unit : ctx.getRouteCalculateUnits()) {
-			if(unit != null && unit.getTablesAndConditions() != null) {
-				map.putAll(unit.getTablesAndConditions());
-			}
-		}
-		
-		return map;
-	}
-
-	private void tryRoute(SchemaConfig schema, RouteResultset rrs, LayerCachePool cachePool) throws SQLNonTransientException {
-		if(rrs.isFinishedRoute())
-		{
-			return;//避免重复路由
-		}
-
-		//无表的select语句直接路由带任一节点
-        if((ctx.getTables() == null || ctx.getTables().size() == 0)&&(ctx.getTableAliasMap()==null||ctx.getTableAliasMap().isEmpty())) {
-			rrs = RouterUtil.routeToSingleNode(rrs, schema.getRandomDataNode(), ctx.getSql());
-			rrs.setFinishedRoute(true);
-			return;
-		}
-//		RouterUtil.tryRouteForTables(schema, ctx, rrs, true, cachePool);
-		SortedSet<RouteResultsetNode> nodeSet = new TreeSet<RouteResultsetNode>();
-		boolean isAllGlobalTable = RouterUtil.isAllGlobalTable(ctx, schema);
-		for (RouteCalculateUnit unit : ctx.getRouteCalculateUnits()) {
-			RouteResultset rrsTmp = RouterUtil.tryRouteForTables(schema, ctx, unit, rrs, true, cachePool);
-			if (rrsTmp != null&&rrsTmp.getNodes()!=null) {
-				for (RouteResultsetNode node : rrsTmp.getNodes()) {
-					nodeSet.add(node);
-				}
-			}
-			if(isAllGlobalTable) {//都是全局表时只计算一遍路由
-				break;
-			}
-		}
-		
-		if(nodeSet.size() == 0) {
-
-            Collection<String> stringCollection= ctx.getTableAliasMap().values() ;
-            for (String table : stringCollection)
-            {
-                if(table!=null&&table.toLowerCase().contains("information_schema."))
-                {
-                    rrs = RouterUtil.routeToSingleNode(rrs, schema.getRandomDataNode(), ctx.getSql());
-                    rrs.setFinishedRoute(true);
-                    return;
-                }
-            }
-			String msg = " find no Route:" + ctx.getSql();
-			LOGGER.warn(msg);
-			throw new SQLNonTransientException(msg);
-		}
-		
-		RouteResultsetNode[] nodes = new RouteResultsetNode[nodeSet.size()];
-		int i = 0;
-		for (Iterator<RouteResultsetNode> iterator = nodeSet.iterator(); iterator.hasNext();) {
-			nodes[i] = (RouteResultsetNode) iterator.next();
-			i++;
-			
-		}
-		
-		rrs.setNodes(nodes);
-		rrs.setFinishedRoute(true);
-	}
-
-
-	protected String getCurentDbType()
-	{
-		return JdbcConstants.MYSQL;
-	}
-
-
-
-
-	protected String getSql( RouteResultset rrs,SQLStatement stmt, boolean isNeedAddLimit)
-	{
-		if(getCurentDbType().equalsIgnoreCase("mysql")&&(isNeedChangeLimit(rrs)||isNeedAddLimit))
-		{
-
-				return stmt.toString();
-
-		}
-
-	 return getCtx().getSql();
-	}
-
-
-	
-	protected boolean isNeedChangeLimit(RouteResultset rrs) {
-		if(rrs.getNodes() == null) {
-			return false;
-		} else {
-			if(rrs.getNodes().length > 1) {
-				return true;
-			}
-			return false;
-		
-		} 
-	}
-	
-	private boolean isNeedCache(SchemaConfig schema, RouteResultset rrs, 
-			MySqlSelectQueryBlock mysqlSelectQuery, Map<String, Map<String, Set<ColumnRoutePair>>> allConditions) {
-		if(ctx.getTables() == null || ctx.getTables().size() == 0 ) {
-			return false;
-		}
-		TableConfig tc = schema.getTables().get(ctx.getTables().get(0));
-		if(tc==null ||(ctx.getTables().size() == 1 && tc.isGlobalTable())
-				) {//|| (ctx.getTables().size() == 1) && tc.getRule() == null && tc.getDataNodes().size() == 1
-			return false;
-		} else {
-			//单表主键查询
-			if(ctx.getTables().size() == 1) {
-				String tableName = ctx.getTables().get(0);
-				String primaryKey = schema.getTables().get(tableName).getPrimaryKey();
-//				schema.getTables().get(ctx.getTables().get(0)).getParentKey() != null;
-				if(ctx.getRouteCalculateUnit().getTablesAndConditions().get(tableName) != null
-						&& ctx.getRouteCalculateUnit().getTablesAndConditions().get(tableName).get(primaryKey) != null 
-						&& tc.getDataNodes().size() > 1) {//有主键条件
-					return false;
-				}
-			//全局表不缓存 
-			}else if(RouterUtil.isAllGlobalTable(ctx, schema)){
-				return false;
-			}
-			return true;
-		}
-	}
-	
-	/**
-	 * 单表且是全局表
-	 * 单表且rule为空且nodeNodes只有一个
-	 * @param schema
-	 * @param rrs
-	 * @param mysqlSelectQuery
-	 * @return
-	 */
-	private boolean isNeedAddLimit(SchemaConfig schema, RouteResultset rrs, 
-			MySqlSelectQueryBlock mysqlSelectQuery, Map<String, Map<String, Set<ColumnRoutePair>>> allConditions) {
-//		ctx.getTablesAndConditions().get(key))
-		  if(rrs.getLimitSize()>-1)
-		  {
-			  return false;
-		  }else
-		if(schema.getDefaultMaxLimit() == -1) {
-			return false;
-		} else if (mysqlSelectQuery.getLimit() != null) {//语句中已有limit
-			return false;
-		} else if(ctx.getTables().size() == 1) {
-			String tableName = ctx.getTables().get(0);
-			TableConfig tableConfig = schema.getTables().get(tableName);
-			if(tableConfig==null)
-			{
-			 return    schema.getDefaultMaxLimit() > -1;   //   找不到则取schema的配置
-			}
-
-			boolean isNeedAddLimit= tableConfig.isNeedAddLimit();
-			if(!isNeedAddLimit)
-			{
-				return false;//优先从配置文件取
-			}
-
-			if(schema.getTables().get(tableName).isGlobalTable()) {
-				return true;
-			}
-
-			String primaryKey = schema.getTables().get(tableName).getPrimaryKey();
-
-//			schema.getTables().get(ctx.getTables().get(0)).getParentKey() != null;
-			if(allConditions.get(tableName) == null) {//无条件
-				return true;
-			}
-			
-			if (allConditions.get(tableName).get(primaryKey) != null) {//条件中带主键
-				return false;
-			}
-			
-			return true;
-		} else if(rrs.hasPrimaryKeyToCache() && ctx.getTables().size() == 1){//只有一个表且条件中有主键,不需要limit了,因为主键只能查到一条记录
-			return false;
-		} else {//多表或无表
-			return false;
-		}
-		
-	}
-	private String getAliaColumn(Map<String, String> aliaColumns,String column ){
-		String alia=aliaColumns.get(column);
-		if (alia==null){
-			if(column.indexOf(".") < 0) {
-				String col = "." + column;
-				String col2 = ".`" + column+"`";
-				//展开aliaColumns，将<c.name,cname>之类的键值对展开成<c.name,cname>和<name,cname>
-				for(Map.Entry<String, String> entry : aliaColumns.entrySet()) {
-					if(entry.getKey().endsWith(col)||entry.getKey().endsWith(col2)) {
-						if(entry.getValue() != null && entry.getValue().indexOf(".") > 0) {
-							return column;
-						}
-						return entry.getValue();
-					}
-				}
-			}
-			
-			return column;
-		}
-		else {
-			return alia;
-		}
-	}
-	
-	private String[] buildGroupByCols(List<SQLExpr> groupByItems,Map<String, String> aliaColumns) {
-		String[] groupByCols = new String[groupByItems.size()]; 
-		for(int i= 0; i < groupByItems.size(); i++) {
-            SQLExpr sqlExpr = groupByItems.get(i);
-            String column = null;
-            if(sqlExpr instanceof SQLIdentifierExpr )
-            {
-                column=((SQLIdentifierExpr) sqlExpr).getName();
-            } else if(sqlExpr instanceof SQLMethodInvokeExpr){
-				column = ((SQLMethodInvokeExpr) sqlExpr).toString();
-			} else if(sqlExpr instanceof MySqlOrderingExpr){
-                //todo czn
-                SQLExpr expr = ((MySqlOrderingExpr) sqlExpr).getExpr();
-
-                if (expr instanceof SQLName)
-                {
-                    column = StringUtil.removeBackquote(((SQLName) expr).getSimpleName());//不要转大写 2015-2-10 sohudo StringUtil.removeBackquote(expr.getSimpleName().toUpperCase());
-                } else
-                {
-                    column = StringUtil.removeBackquote(expr.toString());
-                }
-            } else if(sqlExpr instanceof SQLPropertyExpr){
-				/**
-				 * 针对子查询别名，例如select id from (select h.id from hotnews h  union select h.title from hotnews h ) as t1 group by t1.id;
-				 */
-				column = sqlExpr.toString();
-			}
-			if(column == null){
-				column = sqlExpr.toString();
-			}
-			int dotIndex=column.indexOf(".") ;
-			int bracketIndex=column.indexOf("(") ;
-			//通过判断含有括号来决定是否为函数列
-			if(dotIndex!=-1&&bracketIndex==-1)
-			{
-				//此步骤得到的column必须是不带.的，有别名的用别名，无别名的用字段名
-				column=column.substring(dotIndex+1) ;
-			}
-			groupByCols[i] = getAliaColumn(aliaColumns,column);//column;
-		}
-		return groupByCols;
-	}
-	
-	protected LinkedHashMap<String, Integer> buildOrderByCols(List<SQLSelectOrderByItem> orderByItems,Map<String, String> aliaColumns) {
-		LinkedHashMap<String, Integer> map = new LinkedHashMap<String, Integer>();
-		for(int i= 0; i < orderByItems.size(); i++) {
-			SQLOrderingSpecification type = orderByItems.get(i).getType();
-            //orderColumn只记录字段名称,因为返回的结果集是不带表名的。
-			SQLExpr expr =  orderByItems.get(i).getExpr();
-			String col;
-			if (expr instanceof SQLName) {
-			   col = ((SQLName)expr).getSimpleName();
-			}
-			else {
-				col =expr.toString();
-			}
-			if(type == null) {
-				type = SQLOrderingSpecification.ASC;
-			}
-			col=getAliaColumn(aliaColumns,col);//此步骤得到的col必须是不带.的，有别名的用别名，无别名的用字段名
-			map.put(col, type == SQLOrderingSpecification.ASC ? OrderCol.COL_ORDER_TYPE_ASC : OrderCol.COL_ORDER_TYPE_DESC);
-		}
-		return map;
-	}
-	
-	private boolean isConditionAlwaysTrue(SQLStatement statement) {
-		SQLSelectStatement selectStmt = (SQLSelectStatement)statement;
-		SQLSelectQuery sqlSelectQuery = selectStmt.getSelect().getQuery();
-		if(sqlSelectQuery instanceof MySqlSelectQueryBlock) {
-			MySqlSelectQueryBlock mysqlSelectQuery = (MySqlSelectQueryBlock)selectStmt.getSelect().getQuery();
-			SQLExpr expr = mysqlSelectQuery.getWhere();
-			
-			Object o = WallVisitorUtils.getValue(expr);
-			if(Boolean.TRUE.equals(o)) {
-				return true;
-			}
-			return false;
-		} else {//union
-			return false;
-		}
-		
-	}
-
-	protected void setLimitIFChange(SQLStatement stmt, RouteResultset rrs, SchemaConfig schema, SQLBinaryOpExpr one, int firstrownum, int lastrownum)
-	{
-		rrs.setLimitStart(firstrownum);
-		rrs.setLimitSize(lastrownum - firstrownum);
-		LayerCachePool tableId2DataNodeCache = (LayerCachePool) MycatServer.getInstance().getCacheService().getCachePool("TableID2DataNodeCache");
-		try
-		{
-			tryRoute(schema, rrs, tableId2DataNodeCache);
-		} catch (SQLNonTransientException e)
-		{
-			throw new RuntimeException(e);
-		}
-		if (isNeedChangeLimit(rrs))
-		{
-			one.setRight(new SQLIntegerExpr(0));
-            String curentDbType ="db2".equalsIgnoreCase(this.getCurentDbType())?"oracle":getCurentDbType();
-            String sql =   SQLUtils.toSQLString(stmt, curentDbType);;
-			rrs.changeNodeSqlAfterAddLimit(schema,getCurentDbType(), sql,0,lastrownum, false);
-			//设置改写后的sql
-			getCtx().setSql(sql);
-		}
-	}
-}
+package io.mycat.route.parser.druid.impl;
+
+import java.sql.SQLNonTransientException;
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.HashMap;
+import java.util.Iterator;
+import java.util.LinkedHashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+import java.util.SortedSet;
+import java.util.TreeSet;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import com.alibaba.druid.sql.SQLUtils;
+import com.alibaba.druid.sql.ast.SQLExpr;
+import com.alibaba.druid.sql.ast.SQLName;
+import com.alibaba.druid.sql.ast.SQLOrderingSpecification;
+import com.alibaba.druid.sql.ast.SQLStatement;
+import com.alibaba.druid.sql.ast.expr.SQLAggregateExpr;
+import com.alibaba.druid.sql.ast.expr.SQLAllColumnExpr;
+import com.alibaba.druid.sql.ast.expr.SQLBinaryOpExpr;
+import com.alibaba.druid.sql.ast.expr.SQLBinaryOperator;
+import com.alibaba.druid.sql.ast.expr.SQLIdentifierExpr;
+import com.alibaba.druid.sql.ast.expr.SQLIntegerExpr;
+import com.alibaba.druid.sql.ast.expr.SQLMethodInvokeExpr;
+import com.alibaba.druid.sql.ast.expr.SQLNumericLiteralExpr;
+import com.alibaba.druid.sql.ast.expr.SQLPropertyExpr;
+import com.alibaba.druid.sql.ast.expr.SQLTextLiteralExpr;
+import com.alibaba.druid.sql.ast.statement.SQLExprTableSource;
+import com.alibaba.druid.sql.ast.statement.SQLJoinTableSource;
+import com.alibaba.druid.sql.ast.statement.SQLSelectGroupByClause;
+import com.alibaba.druid.sql.ast.statement.SQLSelectItem;
+import com.alibaba.druid.sql.ast.statement.SQLSelectOrderByItem;
+import com.alibaba.druid.sql.ast.statement.SQLSelectQuery;
+import com.alibaba.druid.sql.ast.statement.SQLSelectQueryBlock;
+import com.alibaba.druid.sql.ast.statement.SQLSelectStatement;
+import com.alibaba.druid.sql.ast.statement.SQLSubqueryTableSource;
+import com.alibaba.druid.sql.ast.statement.SQLTableSource;
+import com.alibaba.druid.sql.dialect.db2.ast.stmt.DB2SelectQueryBlock;
+import com.alibaba.druid.sql.dialect.db2.visitor.DB2OutputVisitor;
+import com.alibaba.druid.sql.dialect.mysql.ast.expr.MySqlOrderingExpr;
+import com.alibaba.druid.sql.dialect.mysql.ast.statement.MySqlSelectQueryBlock;
+import com.alibaba.druid.sql.dialect.mysql.ast.statement.MySqlSelectQueryBlock.Limit;
+import com.alibaba.druid.sql.dialect.mysql.ast.statement.MySqlUnionQuery;
+import com.alibaba.druid.sql.dialect.mysql.visitor.MySqlOutputVisitor;
+import com.alibaba.druid.sql.dialect.mysql.visitor.MySqlSchemaStatVisitor;
+import com.alibaba.druid.sql.dialect.oracle.ast.stmt.OracleSelectQueryBlock;
+import com.alibaba.druid.sql.dialect.oracle.visitor.OracleOutputVisitor;
+import com.alibaba.druid.sql.dialect.postgresql.ast.stmt.PGSelectQueryBlock;
+import com.alibaba.druid.sql.dialect.postgresql.visitor.PGOutputVisitor;
+import com.alibaba.druid.sql.dialect.sqlserver.ast.SQLServerSelectQueryBlock;
+import com.alibaba.druid.sql.visitor.SQLASTOutputVisitor;
+import com.alibaba.druid.util.JdbcConstants;
+import com.alibaba.druid.wall.spi.WallVisitorUtils;
+
+import io.mycat.MycatServer;
+import io.mycat.cache.LayerCachePool;
+import io.mycat.config.ErrorCode;
+import io.mycat.config.model.SchemaConfig;
+import io.mycat.config.model.TableConfig;
+import io.mycat.route.RouteResultset;
+import io.mycat.route.RouteResultsetNode;
+import io.mycat.route.parser.druid.MycatSchemaStatVisitor;
+import io.mycat.route.parser.druid.RouteCalculateUnit;
+import io.mycat.route.util.RouterUtil;
+import io.mycat.sqlengine.mpp.ColumnRoutePair;
+import io.mycat.sqlengine.mpp.HavingCols;
+import io.mycat.sqlengine.mpp.MergeCol;
+import io.mycat.sqlengine.mpp.OrderCol;
+import io.mycat.util.ObjectUtil;
+import io.mycat.util.StringUtil;
+
+public class DruidSelectParser extends DefaultDruidParser {
+	private final Logger logger = LoggerFactory.getLogger(getClass());
+
+
+    protected boolean isNeedParseOrderAgg=true;
+
+    @Override
+	public void statementParse(SchemaConfig schema, RouteResultset rrs, SQLStatement stmt) {
+		SQLSelectStatement selectStmt = (SQLSelectStatement)stmt;
+		SQLSelectQuery sqlSelectQuery = selectStmt.getSelect().getQuery();
+		if(sqlSelectQuery instanceof MySqlSelectQueryBlock) {
+			MySqlSelectQueryBlock mysqlSelectQuery = (MySqlSelectQueryBlock)selectStmt.getSelect().getQuery();
+
+				 parseOrderAggGroupMysql(schema, stmt,rrs, mysqlSelectQuery);
+				 //更改canRunInReadDB属性
+				 if ((mysqlSelectQuery.isForUpdate() || mysqlSelectQuery.isLockInShareMode()) && rrs.isAutocommit() == false)
+				 {
+					 rrs.setCanRunInReadDB(false);
+				 }
+
+		} else if (sqlSelectQuery instanceof MySqlUnionQuery) { 
+//			MySqlUnionQuery unionQuery = (MySqlUnionQuery)sqlSelectQuery;
+//			MySqlSelectQueryBlock left = (MySqlSelectQueryBlock)unionQuery.getLeft();
+//			MySqlSelectQueryBlock right = (MySqlSelectQueryBlock)unionQuery.getLeft();
+//			System.out.println();
+		}
+	}
+	protected void parseOrderAggGroupMysql(SchemaConfig schema, SQLStatement stmt, RouteResultset rrs, MySqlSelectQueryBlock mysqlSelectQuery)
+	{
+		MySqlSchemaStatVisitor visitor = new MySqlSchemaStatVisitor();
+		stmt.accept(visitor);
+//		rrs.setGroupByCols((String[])visitor.getGroupByColumns().toArray());
+		if(!isNeedParseOrderAgg)
+        {
+            return;
+        }
+		Map<String, String> aliaColumns = parseAggGroupCommon(schema, stmt, rrs, mysqlSelectQuery);
+
+		//setOrderByCols
+		if(mysqlSelectQuery.getOrderBy() != null) {
+			List<SQLSelectOrderByItem> orderByItems = mysqlSelectQuery.getOrderBy().getItems();
+			rrs.setOrderByCols(buildOrderByCols(orderByItems,aliaColumns));
+		}
+        isNeedParseOrderAgg=false;
+	}
+	protected Map<String, String> parseAggGroupCommon(SchemaConfig schema, SQLStatement stmt, RouteResultset rrs, SQLSelectQueryBlock mysqlSelectQuery)
+	{
+		Map<String, String> aliaColumns = new HashMap<String, String>();
+		Map<String, Integer> aggrColumns = new HashMap<String, Integer>();
+		// Added by winbill, 20160314, for having clause, Begin ==>
+		List<String> havingColsName = new ArrayList<String>();
+		// Added by winbill, 20160314, for having clause, End  <==
+		List<SQLSelectItem> selectList = mysqlSelectQuery.getSelectList();
+        boolean isNeedChangeSql=false;
+        int size = selectList.size();
+        boolean isDistinct=mysqlSelectQuery.getDistionOption()==2;
+        for (int i = 0; i < size; i++)
+		{
+			SQLSelectItem item = selectList.get(i);
+
+			if (item.getExpr() instanceof SQLAggregateExpr)
+			{
+				SQLAggregateExpr expr = (SQLAggregateExpr) item.getExpr();
+				String method = expr.getMethodName();
+                boolean isHasArgument=!expr.getArguments().isEmpty();
+                if(isHasArgument)
+                {
+                    String aggrColName = method + "(" + expr.getArguments().get(0) + ")";   // Added by winbill, 20160314, for having clause
+                    havingColsName.add(aggrColName);       // Added by winbill, 20160314, for having clause
+                }
+				//只处理有别名的情况，无别名添加别名，否则某些数据库会得不到正确结果处理
+				int mergeType = MergeCol.getMergeType(method);
+                if (MergeCol.MERGE_AVG == mergeType&&isRoutMultiNode(schema,rrs))
+                {    //跨分片avg需要特殊处理，直接avg结果是不对的
+                    String colName = item.getAlias() != null ? item.getAlias() : method + i;
+                    SQLSelectItem sum =new SQLSelectItem();
+                    String sumColName = colName + "SUM";
+                    sum.setAlias(sumColName);
+                    SQLAggregateExpr sumExp =new SQLAggregateExpr("SUM");
+                    ObjectUtil.copyProperties(expr,sumExp);
+                    sumExp.getArguments().addAll(expr.getArguments());
+                    sumExp.setMethodName("SUM");
+                    sum.setExpr(sumExp);
+                    selectList.set(i, sum);
+                    aggrColumns.put(sumColName, MergeCol.MERGE_SUM);
+                    havingColsName.add(sumColName);    // Added by winbill, 20160314, for having clause
+                    havingColsName.add(item.getAlias() != null ? item.getAlias() : "");    // Added by winbill, 20160314, two aliases for AVG
+
+                    SQLSelectItem count =new SQLSelectItem();
+                    String countColName = colName + "COUNT";
+                    count.setAlias(countColName);
+                    SQLAggregateExpr countExp = new SQLAggregateExpr("COUNT");
+                    ObjectUtil.copyProperties(expr,countExp);
+                    countExp.getArguments().addAll(expr.getArguments());
+                    countExp.setMethodName("COUNT");
+                    count.setExpr(countExp);
+                    selectList.add(count);
+                    aggrColumns.put(countColName, MergeCol.MERGE_COUNT);
+
+                    isNeedChangeSql=true;
+                    aggrColumns.put(colName, mergeType);
+                    rrs.setHasAggrColumn(true);
+                } else if (MergeCol.MERGE_UNSUPPORT != mergeType){
+					String aggColName = null;
+					StringBuilder sb = new StringBuilder();
+					if(mysqlSelectQuery instanceof MySqlSelectQueryBlock) {
+						expr.accept(new MySqlOutputVisitor(sb));
+					} else if(mysqlSelectQuery instanceof OracleSelectQueryBlock) {
+						expr.accept(new OracleOutputVisitor(sb));
+					} else if(mysqlSelectQuery instanceof PGSelectQueryBlock){
+						expr.accept(new PGOutputVisitor(sb));
+					} else if(mysqlSelectQuery instanceof SQLServerSelectQueryBlock) {
+						expr.accept(new SQLASTOutputVisitor(sb));
+					} else if(mysqlSelectQuery instanceof DB2SelectQueryBlock) {
+						expr.accept(new DB2OutputVisitor(sb));
+					}
+					aggColName = sb.toString();
+
+					if (item.getAlias() != null && item.getAlias().length() > 0)
+					{
+						aggrColumns.put(item.getAlias(), mergeType);
+						aliaColumns.put(aggColName,item.getAlias());
+					} else
+					{   //如果不加，jdbc方式时取不到正确结果   ;修改添加别名
+							item.setAlias(method + i);
+							aggrColumns.put(method + i, mergeType);
+							aliaColumns.put(aggColName, method + i);
+                            isNeedChangeSql=true;
+					}
+					rrs.setHasAggrColumn(true);
+					havingColsName.add(item.getAlias());   // Added by winbill, 20160314, for having clause
+					havingColsName.add("");                // Added by winbill, 20160314, one alias for non-AVG
+				}
+			} else
+			{
+				if (!(item.getExpr() instanceof SQLAllColumnExpr))
+				{
+					String alia = item.getAlias();
+					String field = getFieldName(item);
+					if (alia == null)
+					{
+						alia = field;
+					}
+					aliaColumns.put(field, alia);
+				}
+			}
+
+		}
+		if(aggrColumns.size() > 0) {
+			rrs.setMergeCols(aggrColumns);
+		}
+
+        //通过优化转换成group by来实现
+        if(isDistinct)
+        {
+            mysqlSelectQuery.setDistionOption(0);
+            SQLSelectGroupByClause   groupBy=new SQLSelectGroupByClause();
+            for (String fieldName : aliaColumns.keySet())
+            {
+                groupBy.addItem(new SQLIdentifierExpr(fieldName));
+            }
+            mysqlSelectQuery.setGroupBy(groupBy);
+            isNeedChangeSql=true;
+        }
+
+
+        //setGroupByCols
+		if(mysqlSelectQuery.getGroupBy() != null) {
+			List<SQLExpr> groupByItems = mysqlSelectQuery.getGroupBy().getItems();
+			String[] groupByCols = buildGroupByCols(groupByItems,aliaColumns);
+			rrs.setGroupByCols(groupByCols);
+			rrs.setHavings(buildGroupByHaving(mysqlSelectQuery.getGroupBy().getHaving(),aliaColumns));
+			rrs.setHasAggrColumn(true);
+			rrs.setHavingColsName(havingColsName.toArray()); // Added by winbill, 20160314, for having clause
+		}
+
+
+        if (isNeedChangeSql)
+        {
+            String sql = stmt.toString();
+            rrs.changeNodeSqlAfterAddLimit(schema,getCurentDbType(),sql,0,-1, false);
+            getCtx().setSql(sql);
+        }
+		return aliaColumns;
+	}
+
+	private HavingCols buildGroupByHaving(SQLExpr having,Map<String, String> aliaColumns ){
+		if (having == null) {
+			return null;
+		}
+
+		SQLBinaryOpExpr expr  = ((SQLBinaryOpExpr) having);
+		SQLExpr left = expr.getLeft();
+		SQLBinaryOperator operator = expr.getOperator();
+		SQLExpr right = expr.getRight();
+
+		String leftValue = null;;
+		if (left instanceof SQLAggregateExpr) {
+			leftValue = ((SQLAggregateExpr) left).getMethodName() + "("
+					+ ((SQLAggregateExpr) left).getArguments().get(0) + ")";
+			String aggrColumnAlias = getAliaColumn(aliaColumns,leftValue);
+			if(aggrColumnAlias != null) { // having聚合函数存在别名
+				expr.setLeft(new SQLIdentifierExpr(aggrColumnAlias));
+				leftValue = aggrColumnAlias;
+			}
+		} else if (left instanceof SQLIdentifierExpr) {
+			leftValue = ((SQLIdentifierExpr) left).getName();
+		}
+
+		String rightValue = null;
+		if (right instanceof  SQLNumericLiteralExpr) {
+			rightValue = right.toString();
+		}else if(right instanceof SQLTextLiteralExpr){
+			rightValue = StringUtil.removeBackquote(right.toString());
+		}
+
+		return new HavingCols(leftValue,rightValue,operator.getName());
+	}
+
+  private boolean isRoutMultiNode(SchemaConfig schema,  RouteResultset rrs)
+  {
+	  if(rrs.getNodes()!=null&&rrs.getNodes().length>1)
+	  {
+		  return true;
+	  }
+	  LayerCachePool tableId2DataNodeCache = (LayerCachePool) MycatServer.getInstance().getCacheService().getCachePool("TableID2DataNodeCache");
+	  try
+	  {
+		  tryRoute(schema, rrs, tableId2DataNodeCache);
+		  if(rrs.getNodes()!=null&&rrs.getNodes().length>1)
+		  {
+			  return true;
+		  }
+	  } catch (SQLNonTransientException e)
+	  {
+		  throw new RuntimeException(e);
+	  }
+	  return false;
+  }
+
+	private String getFieldName(SQLSelectItem item){
+		if ((item.getExpr() instanceof SQLPropertyExpr)||(item.getExpr() instanceof SQLMethodInvokeExpr)
+				|| (item.getExpr() instanceof SQLIdentifierExpr) || item.getExpr() instanceof SQLBinaryOpExpr) {			
+			return item.getExpr().toString();//字段别名
+		}
+		else {
+			return item.toString();
+		}
+	}
+	
+	/**
+	 * 现阶段目标为 有一个只涉及到一张表的子查询时,先执行子查询,获得返回结果后,改写原有sql继续执行,得到最终结果.
+	 * 在这种情况下,原sql不需要继续解析.
+	 * 使用catlet 的情况也不再继续解析.
+	 */
+	@Override
+	public boolean afterVisitorParser(RouteResultset rrs, SQLStatement stmt, MycatSchemaStatVisitor visitor) {
+		int subQuerySize = visitor.getSubQuerys().size();
+		
+		if(subQuerySize==0&&ctx.getTables().size()==2){ //两表关联,考虑使用catlet
+		    if(ctx.getVisitor().getConditions() !=null && ctx.getVisitor().getConditions().size()>0){
+		    	return true;
+			}
+		}else if(subQuerySize==1){     //只涉及一张表的子查询,使用  MiddlerResultHandler 获取中间结果后,改写原有 sql 继续执行 TODO 后期可能会考虑多个.
+			SQLSelectQuery sqlSelectQuery = visitor.getSubQuerys().iterator().next().getQuery();
+			if(((MySqlSelectQueryBlock)sqlSelectQuery).getFrom() instanceof SQLExprTableSource) {
+				return true;
+			}
+		}
+		
+		return super.afterVisitorParser(rrs, stmt, visitor);
+	}
+	
+	/**
+	 * 改写sql：需要加limit的加上
+	 */
+	@Override
+	public void changeSql(SchemaConfig schema, RouteResultset rrs, SQLStatement stmt,LayerCachePool cachePool) throws SQLNonTransientException {
+
+		tryRoute(schema, rrs, cachePool);
+
+		rrs.copyLimitToNodes();
+		
+		SQLSelectStatement selectStmt = (SQLSelectStatement)stmt;
+		SQLSelectQuery sqlSelectQuery = selectStmt.getSelect().getQuery();
+		if(sqlSelectQuery instanceof MySqlSelectQueryBlock) {
+			MySqlSelectQueryBlock mysqlSelectQuery = (MySqlSelectQueryBlock)selectStmt.getSelect().getQuery();
+			int limitStart = 0;
+			int limitSize = schema.getDefaultMaxLimit();
+
+			//clear group having
+			SQLSelectGroupByClause groupByClause = mysqlSelectQuery.getGroupBy();
+			// Modified by winbill, 20160614, do NOT include having clause when routing to multiple nodes
+			if(groupByClause != null && groupByClause.getHaving() != null && isRoutMultiNode(schema,rrs)){
+				groupByClause.setHaving(null);
+			}
+			
+			Map<String, Map<String, Set<ColumnRoutePair>>> allConditions = getAllConditions();
+			boolean isNeedAddLimit = isNeedAddLimit(schema, rrs, mysqlSelectQuery, allConditions);
+			if(isNeedAddLimit) {
+				Limit limit = new Limit();
+				limit.setRowCount(new SQLIntegerExpr(limitSize));
+				mysqlSelectQuery.setLimit(limit);
+				rrs.setLimitSize(limitSize);
+			    String sql= getSql(rrs, stmt, isNeedAddLimit);
+				rrs.changeNodeSqlAfterAddLimit(schema, getCurentDbType(), sql, 0, limitSize, true);
+
+			}
+			Limit limit = mysqlSelectQuery.getLimit();
+			if(limit != null&&!isNeedAddLimit) {
+				SQLIntegerExpr offset = (SQLIntegerExpr)limit.getOffset();
+				SQLIntegerExpr count = (SQLIntegerExpr)limit.getRowCount();
+				if(offset != null) {
+					limitStart = offset.getNumber().intValue();
+					rrs.setLimitStart(limitStart);
+				} 
+				if(count != null) {
+					limitSize = count.getNumber().intValue();
+					rrs.setLimitSize(limitSize);
+				}
+
+				if(isNeedChangeLimit(rrs)) {
+					Limit changedLimit = new Limit();
+					changedLimit.setRowCount(new SQLIntegerExpr(limitStart + limitSize));
+					
+					if(offset != null) {
+						if(limitStart < 0) {
+							String msg = "You have an error in your SQL syntax; check the manual that " +
+									"corresponds to your MySQL server version for the right syntax to use near '" + limitStart + "'";
+							throw new SQLNonTransientException(ErrorCode.ER_PARSE_ERROR + " - " + msg);
+						} else {
+							changedLimit.setOffset(new SQLIntegerExpr(0));
+							
+						}
+					}
+					
+					mysqlSelectQuery.setLimit(changedLimit);
+
+                    String sql= getSql(rrs, stmt, isNeedAddLimit);
+					rrs.changeNodeSqlAfterAddLimit(schema,getCurentDbType(),sql,0, limitStart + limitSize, true);
+
+					//设置改写后的sql
+					ctx.setSql(sql);
+
+				}   else
+				{
+
+                        rrs.changeNodeSqlAfterAddLimit(schema,getCurentDbType(),getCtx().getSql(),rrs.getLimitStart(), rrs.getLimitSize(), true);
+					//	ctx.setSql(nativeSql);
+
+				}
+				
+
+			}
+			
+			if(rrs.isDistTable()){
+				MySqlSelectQueryBlock query = (MySqlSelectQueryBlock) selectStmt.getSelect().getQuery();
+				SQLTableSource from2 = query.getFrom();
+				if (from2 instanceof SQLSubqueryTableSource) {
+					SQLSubqueryTableSource from = (SQLSubqueryTableSource) from2;
+					MySqlSelectQueryBlock query2 = (MySqlSelectQueryBlock) from.getSelect().getQuery();
+					sqlRoute(rrs, selectStmt, mysqlSelectQuery, query2);
+				} else {
+					sqlRoute(rrs, selectStmt, mysqlSelectQuery, query);
+				}
+				logger.info("执行sql： " + selectStmt.toString());
+			}
+			
+			rrs.setCacheAble(isNeedCache(schema, rrs, mysqlSelectQuery, allConditions));
+		}
+		
+	}
+	private void sqlRoute(RouteResultset rrs, SQLSelectStatement selectStmt, MySqlSelectQueryBlock mysqlSelectQuery,
+			MySqlSelectQueryBlock query) throws SQLNonTransientException {
+		SQLTableSource from2 = query.getFrom();
+		SQLExprTableSource left2 = (SQLExprTableSource) getExpr(from2);
+		String alias = left2.getAlias();
+		
+		left2.setAlias(alias);
+		
+		SQLTableSource from1 = mysqlSelectQuery.getFrom();
+
+		for (RouteResultsetNode node : rrs.getNodes()) {
+			/*
+			SQLExprTableSource from2 = new SQLExprTableSource(sqlIdentifierExpr);
+			from2.setAlias(alias);
+			*/
+			SQLIdentifierExpr sqlIdentifierExpr = new SQLIdentifierExpr();
+			sqlIdentifierExpr.setParent(from1);
+			sqlIdentifierExpr.setName(node.getSubTableName());
+			left2.setExpr(sqlIdentifierExpr);
+			
+			//mysqlSelectQuery.setFrom(left2);
+			node.setStatement(selectStmt.toString());
+		}
+	}
+	
+	private SQLTableSource getExpr(SQLTableSource source) throws SQLNonTransientException {
+		if (source instanceof SQLExprTableSource) {
+			return source;
+		} else if (source instanceof SQLJoinTableSource) {
+			SQLJoinTableSource joinsource = (SQLJoinTableSource) source;
+			SQLTableSource right = joinsource.getRight();
+			
+			if (right instanceof SQLJoinTableSource) {
+				
+			} else {
+				
+			}
+			
+			return getExpr(joinsource.getLeft());
+		} else {
+			throw new SQLNonTransientException(ErrorCode.ER_PARSE_ERROR + " - " + "sql不支持");
+		}
+	}
+	
+	/**
+	 * 获取所有的条件：因为可能被or语句拆分成多个RouteCalculateUnit，条件分散了
+	 * @return
+	 */
+	private Map<String, Map<String, Set<ColumnRoutePair>>> getAllConditions() {
+		Map<String, Map<String, Set<ColumnRoutePair>>> map = new HashMap<String, Map<String, Set<ColumnRoutePair>>>();
+		for(RouteCalculateUnit unit : ctx.getRouteCalculateUnits()) {
+			if(unit != null && unit.getTablesAndConditions() != null) {
+				map.putAll(unit.getTablesAndConditions());
+			}
+		}
+		
+		return map;
+	}
+
+	private void tryRoute(SchemaConfig schema, RouteResultset rrs, LayerCachePool cachePool) throws SQLNonTransientException {
+		if(rrs.isFinishedRoute())
+		{
+			return;//避免重复路由
+		}
+
+		//无表的select语句直接路由带任一节点
+        if((ctx.getTables() == null || ctx.getTables().size() == 0)&&(ctx.getTableAliasMap()==null||ctx.getTableAliasMap().isEmpty())) {
+			rrs = RouterUtil.routeToSingleNode(rrs, schema.getRandomDataNode(), ctx.getSql());
+			rrs.setFinishedRoute(true);
+			return;
+		}
+//		RouterUtil.tryRouteForTables(schema, ctx, rrs, true, cachePool);
+		SortedSet<RouteResultsetNode> nodeSet = new TreeSet<RouteResultsetNode>();
+		boolean isAllGlobalTable = RouterUtil.isAllGlobalTable(ctx, schema);
+		for (RouteCalculateUnit unit : ctx.getRouteCalculateUnits()) {
+			RouteResultset rrsTmp = RouterUtil.tryRouteForTables(schema, ctx, unit, rrs, true, cachePool);
+			if (rrsTmp != null&&rrsTmp.getNodes()!=null) {
+				for (RouteResultsetNode node : rrsTmp.getNodes()) {
+					nodeSet.add(node);
+				}
+			}
+			if(isAllGlobalTable) {//都是全局表时只计算一遍路由
+				break;
+			}
+		}
+		
+		if(nodeSet.size() == 0) {
+
+            Collection<String> stringCollection= ctx.getTableAliasMap().values() ;
+            for (String table : stringCollection)
+            {
+                if(table!=null&&table.toLowerCase().contains("information_schema."))
+                {
+                    rrs = RouterUtil.routeToSingleNode(rrs, schema.getRandomDataNode(), ctx.getSql());
+                    rrs.setFinishedRoute(true);
+                    return;
+                }
+            }
+			String msg = " find no Route:" + ctx.getSql();
+			LOGGER.warn(msg);
+			throw new SQLNonTransientException(msg);
+		}
+		
+		RouteResultsetNode[] nodes = new RouteResultsetNode[nodeSet.size()];
+		int i = 0;
+		for (Iterator<RouteResultsetNode> iterator = nodeSet.iterator(); iterator.hasNext();) {
+			nodes[i] = (RouteResultsetNode) iterator.next();
+			i++;
+			
+		}
+		
+		rrs.setNodes(nodes);
+		rrs.setFinishedRoute(true);
+	}
+
+
+	protected String getCurentDbType()
+	{
+		return JdbcConstants.MYSQL;
+	}
+
+
+
+
+	protected String getSql( RouteResultset rrs,SQLStatement stmt, boolean isNeedAddLimit)
+	{
+		if(getCurentDbType().equalsIgnoreCase("mysql")&&(isNeedChangeLimit(rrs)||isNeedAddLimit))
+		{
+
+				return stmt.toString();
+
+		}
+
+	 return getCtx().getSql();
+	}
+
+
+	
+	protected boolean isNeedChangeLimit(RouteResultset rrs) {
+		if(rrs.getNodes() == null) {
+			return false;
+		} else {
+			if(rrs.getNodes().length > 1) {
+				return true;
+			}
+			return false;
+		
+		} 
+	}
+	
+	private boolean isNeedCache(SchemaConfig schema, RouteResultset rrs, 
+			MySqlSelectQueryBlock mysqlSelectQuery, Map<String, Map<String, Set<ColumnRoutePair>>> allConditions) {
+		if(ctx.getTables() == null || ctx.getTables().size() == 0 ) {
+			return false;
+		}
+		TableConfig tc = schema.getTables().get(ctx.getTables().get(0));
+		if(tc==null ||(ctx.getTables().size() == 1 && tc.isGlobalTable())
+				) {//|| (ctx.getTables().size() == 1) && tc.getRule() == null && tc.getDataNodes().size() == 1
+			return false;
+		} else {
+			//单表主键查询
+			if(ctx.getTables().size() == 1) {
+				String tableName = ctx.getTables().get(0);
+				String primaryKey = schema.getTables().get(tableName).getPrimaryKey();
+//				schema.getTables().get(ctx.getTables().get(0)).getParentKey() != null;
+				if(ctx.getRouteCalculateUnit().getTablesAndConditions().get(tableName) != null
+						&& ctx.getRouteCalculateUnit().getTablesAndConditions().get(tableName).get(primaryKey) != null 
+						&& tc.getDataNodes().size() > 1) {//有主键条件
+					return false;
+				}
+			//全局表不缓存 
+			}else if(RouterUtil.isAllGlobalTable(ctx, schema)){
+				return false;
+			}
+			return true;
+		}
+	}
+	
+	/**
+	 * 单表且是全局表
+	 * 单表且rule为空且nodeNodes只有一个
+	 * @param schema
+	 * @param rrs
+	 * @param mysqlSelectQuery
+	 * @return
+	 */
+	private boolean isNeedAddLimit(SchemaConfig schema, RouteResultset rrs, 
+			MySqlSelectQueryBlock mysqlSelectQuery, Map<String, Map<String, Set<ColumnRoutePair>>> allConditions) {
+//		ctx.getTablesAndConditions().get(key))
+		  if(rrs.getLimitSize()>-1)
+		  {
+			  return false;
+		  }else
+		if(schema.getDefaultMaxLimit() == -1) {
+			return false;
+		} else if (mysqlSelectQuery.getLimit() != null) {//语句中已有limit
+			return false;
+		} else if(ctx.getTables().size() == 1) {
+			String tableName = ctx.getTables().get(0);
+			TableConfig tableConfig = schema.getTables().get(tableName);
+			if(tableConfig==null)
+			{
+			 return    schema.getDefaultMaxLimit() > -1;   //   找不到则取schema的配置
+			}
+
+			boolean isNeedAddLimit= tableConfig.isNeedAddLimit();
+			if(!isNeedAddLimit)
+			{
+				return false;//优先从配置文件取
+			}
+
+			if(schema.getTables().get(tableName).isGlobalTable()) {
+				return true;
+			}
+
+			String primaryKey = schema.getTables().get(tableName).getPrimaryKey();
+
+//			schema.getTables().get(ctx.getTables().get(0)).getParentKey() != null;
+			if(allConditions.get(tableName) == null) {//无条件
+				return true;
+			}
+			
+			if (allConditions.get(tableName).get(primaryKey) != null) {//条件中带主键
+				return false;
+			}
+			
+			return true;
+		} else if(rrs.hasPrimaryKeyToCache() && ctx.getTables().size() == 1){//只有一个表且条件中有主键,不需要limit了,因为主键只能查到一条记录
+			return false;
+		} else {//多表或无表
+			return false;
+		}
+		
+	}
+	private String getAliaColumn(Map<String, String> aliaColumns,String column ){
+		String alia=aliaColumns.get(column);
+		if (alia==null){
+			if(column.indexOf(".") < 0) {
+				String col = "." + column;
+				String col2 = ".`" + column+"`";
+				//展开aliaColumns，将<c.name,cname>之类的键值对展开成<c.name,cname>和<name,cname>
+				for(Map.Entry<String, String> entry : aliaColumns.entrySet()) {
+					if(entry.getKey().endsWith(col)||entry.getKey().endsWith(col2)) {
+						if(entry.getValue() != null && entry.getValue().indexOf(".") > 0) {
+							return column;
+						}
+						return entry.getValue();
+					}
+				}
+			}
+			
+			return column;
+		}
+		else {
+			return alia;
+		}
+	}
+	
+	private String[] buildGroupByCols(List<SQLExpr> groupByItems,Map<String, String> aliaColumns) {
+		String[] groupByCols = new String[groupByItems.size()]; 
+		for(int i= 0; i < groupByItems.size(); i++) {
+            SQLExpr sqlExpr = groupByItems.get(i);
+            String column = null;
+            if(sqlExpr instanceof SQLIdentifierExpr )
+            {
+                column=((SQLIdentifierExpr) sqlExpr).getName();
+            } else if(sqlExpr instanceof SQLMethodInvokeExpr){
+				column = ((SQLMethodInvokeExpr) sqlExpr).toString();
+			} else if(sqlExpr instanceof MySqlOrderingExpr){
+                //todo czn
+                SQLExpr expr = ((MySqlOrderingExpr) sqlExpr).getExpr();
+
+                if (expr instanceof SQLName)
+                {
+                    column = StringUtil.removeBackquote(((SQLName) expr).getSimpleName());//不要转大写 2015-2-10 sohudo StringUtil.removeBackquote(expr.getSimpleName().toUpperCase());
+                } else
+                {
+                    column = StringUtil.removeBackquote(expr.toString());
+                }
+            } else if(sqlExpr instanceof SQLPropertyExpr){
+				/**
+				 * 针对子查询别名，例如select id from (select h.id from hotnews h  union select h.title from hotnews h ) as t1 group by t1.id;
+				 */
+				column = sqlExpr.toString();
+			}
+			if(column == null){
+				column = sqlExpr.toString();
+			}
+			int dotIndex=column.indexOf(".") ;
+			int bracketIndex=column.indexOf("(") ;
+			//通过判断含有括号来决定是否为函数列
+			if(dotIndex!=-1&&bracketIndex==-1)
+			{
+				//此步骤得到的column必须是不带.的，有别名的用别名，无别名的用字段名
+				column=column.substring(dotIndex+1) ;
+			}
+			groupByCols[i] = getAliaColumn(aliaColumns,column);//column;
+		}
+		return groupByCols;
+	}
+	
+	protected LinkedHashMap<String, Integer> buildOrderByCols(List<SQLSelectOrderByItem> orderByItems,Map<String, String> aliaColumns) {
+		LinkedHashMap<String, Integer> map = new LinkedHashMap<String, Integer>();
+		for(int i= 0; i < orderByItems.size(); i++) {
+			SQLOrderingSpecification type = orderByItems.get(i).getType();
+            //orderColumn只记录字段名称,因为返回的结果集是不带表名的。
+			SQLExpr expr =  orderByItems.get(i).getExpr();
+			String col;
+			if (expr instanceof SQLName) {
+			   col = ((SQLName)expr).getSimpleName();
+			}
+			else {
+				col =expr.toString();
+			}
+			if(type == null) {
+				type = SQLOrderingSpecification.ASC;
+			}
+			col=getAliaColumn(aliaColumns,col);//此步骤得到的col必须是不带.的，有别名的用别名，无别名的用字段名
+			map.put(col, type == SQLOrderingSpecification.ASC ? OrderCol.COL_ORDER_TYPE_ASC : OrderCol.COL_ORDER_TYPE_DESC);
+		}
+		return map;
+	}
+	
+	private boolean isConditionAlwaysTrue(SQLStatement statement) {
+		SQLSelectStatement selectStmt = (SQLSelectStatement)statement;
+		SQLSelectQuery sqlSelectQuery = selectStmt.getSelect().getQuery();
+		if(sqlSelectQuery instanceof MySqlSelectQueryBlock) {
+			MySqlSelectQueryBlock mysqlSelectQuery = (MySqlSelectQueryBlock)selectStmt.getSelect().getQuery();
+			SQLExpr expr = mysqlSelectQuery.getWhere();
+			
+			Object o = WallVisitorUtils.getValue(expr);
+			if(Boolean.TRUE.equals(o)) {
+				return true;
+			}
+			return false;
+		} else {//union
+			return false;
+		}
+		
+	}
+
+	protected void setLimitIFChange(SQLStatement stmt, RouteResultset rrs, SchemaConfig schema, SQLBinaryOpExpr one, int firstrownum, int lastrownum)
+	{
+		rrs.setLimitStart(firstrownum);
+		rrs.setLimitSize(lastrownum - firstrownum);
+		LayerCachePool tableId2DataNodeCache = (LayerCachePool) MycatServer.getInstance().getCacheService().getCachePool("TableID2DataNodeCache");
+		try
+		{
+			tryRoute(schema, rrs, tableId2DataNodeCache);
+		} catch (SQLNonTransientException e)
+		{
+			throw new RuntimeException(e);
+		}
+		if (isNeedChangeLimit(rrs))
+		{
+			one.setRight(new SQLIntegerExpr(0));
+            String curentDbType ="db2".equalsIgnoreCase(this.getCurentDbType())?"oracle":getCurentDbType();
+            String sql =   SQLUtils.toSQLString(stmt, curentDbType);;
+			rrs.changeNodeSqlAfterAddLimit(schema,getCurentDbType(), sql,0,lastrownum, false);
+			//设置改写后的sql
+			getCtx().setSql(sql);
+		}
+	}
+}