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Merge pull request #41 from rareddy/paging
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Adding the support for the Page support at the top level as well as a…
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@ani-sha
ani-sha authored Sep 22, 2020
2 parents 1a124d6 + 0a1f555 commit f00d005
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Showing 2 changed files with 303 additions and 101 deletions.
120 changes: 97 additions & 23 deletions engine/src/main/java/io/graphqlcrud/SQLQueryBuilderVisitor.java
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Original file line number Diff line number Diff line change
Expand Up @@ -23,6 +23,7 @@
import static org.jooq.impl.DSL.table;
import static org.jooq.impl.DSL.val;

import java.math.BigInteger;
import java.util.ArrayList;
import java.util.LinkedHashMap;
import java.util.List;
Expand All @@ -36,13 +37,14 @@
import org.jooq.Record;
import org.jooq.SQLDialect;
import org.jooq.SelectSelectStep;
import org.jooq.Table;
import org.jooq.impl.DSL;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import graphql.language.Argument;
import graphql.language.Field;
import graphql.language.IntValue;
import graphql.language.ObjectField;
import graphql.language.ObjectValue;
import graphql.language.Value;
import graphql.schema.GraphQLFieldDefinition;
Expand All @@ -69,6 +71,23 @@ private static class VisitorContext {
Map<String, org.jooq.Field<?>> selectedColumns = new LinkedHashMap<>();
Map<String, Field> selectedFields = new LinkedHashMap<>();
org.jooq.Condition condition;
AliasedTable table;
Page page;
List<org.jooq.Field<?>> orderby;
}

private static class Page {
BigInteger limit;
BigInteger offset;
}

private class AliasedTable {
String name;
String alias;
public AliasedTable(String name, String alias) {
this.name = name;
this.alias = alias;
}
}

private Stack<VisitorContext> stack = new Stack<>();
Expand Down Expand Up @@ -112,30 +131,28 @@ public void startVisitObject(Field field, GraphQLFieldDefinition definition, Gra

if (sqlDirective != null && sqlDirective.getPrimaryFields() != null) {
String aliasRight = alias(this.inc.getAndIncrement());
Table<Record> right = buildTable(definition, aliasRight);
AliasedTable right = buildTable(definition, aliasRight);

SelectSelectStep<Record> select = this.create.select();

// add from
select.from(right);

// build where clause based on join
Condition where = null;
for (int key = 0; key < sqlDirective.getPrimaryFields().size(); key++) {
Condition cond = field(name(aliasLeft, sqlDirective.getPrimaryFields().get(key)))
.eq(field(name(aliasRight, sqlDirective.getForeignFields().get(key))));
.eq(field(name(sqlDirective.getForeignFields().get(key))));
if (key == 0) {
where = cond;
} else {
where = where.and(cond);
}
}
select.where(where);

// next level deep as context
vctx = new VisitorContext();
vctx.table = right;
vctx.alias = aliasRight;
vctx.selectClause = select;
vctx.condition = where;

this.stack.push(vctx);
} else {
Expand All @@ -147,14 +164,37 @@ public void startVisitObject(Field field, GraphQLFieldDefinition definition, Gra
public void endVisitObject(Field field, GraphQLFieldDefinition rootDefinition, GraphQLObjectType type) {
VisitorContext vctx = this.stack.pop();

SelectSelectStep<Record> select = this.create.select();
select.from(vctx.table.name);

// add orderby
//List<String> identityColumns = getIdentityColumns(type);
//addOrderBy(vctx, identityColumns);
if (vctx.orderby == null) {
List<String> identityColumns = getIdentityColumns(type);
List<org.jooq.Field<?>> orderby = new ArrayList<>();
identityColumns.stream().forEach(col -> {
org.jooq.Field<?> f = field(name(col));
orderby.add(f);
});
select.orderBy(orderby);
} else {
select.orderBy(vctx.orderby);
}

// add where
// has limit/offset
if (vctx.page != null) {
if (vctx.page.limit != null) {
select.limit(vctx.page.limit.intValue());
}
if (vctx.page.offset != null) {
select.offset(vctx.page.offset.intValue());
}
}

// has where clause
if (vctx.condition != null) {
vctx.selectClause.where(vctx.condition);
select.where(vctx.condition);
}
vctx.selectClause.from(table(select).as(vctx.table.alias));

// build the nested json object
List<JSONEntry<?>> list = new ArrayList<>();
Expand All @@ -169,32 +209,32 @@ public void endVisitObject(Field field, GraphQLFieldDefinition rootDefinition, G
this.stack.peek().selectedColumns.put(field.getName(), json);
}

private void addOrderBy(VisitorContext vctx, List<String> identityColumns) {
private List<org.jooq.Field<?>> buildOrderBy(String alias, List<String> identityColumns) {
List<org.jooq.Field<?>> orderby = new ArrayList<>();
identityColumns.stream().forEach(col -> {
org.jooq.Field<?> f = field(name(vctx.alias, col));
org.jooq.Field<?> f = field(name(alias, col));
orderby.add(f);
});
vctx.selectClause.orderBy(orderby);
return orderby;
}

@Override
public void startVisitRootObject(Field rootField, GraphQLFieldDefinition rootDefinition, GraphQLObjectType type) {
VisitorContext vctx = new VisitorContext();
SQLDirective sqlDirective = SQLDirective.find(type.getDirectives());
if (sqlDirective == null) {
throw new RuntimeException("No SQL Directive found on field " + rootField.getName());
}

String alias = alias(this.inc.getAndIncrement());
Table<Record> table = table(sqlDirective.getTableName()).as(alias);
AliasedTable table = new AliasedTable(sqlDirective.getTableName(), alias);

SelectSelectStep<Record> select = this.create.select();

// add from
select.from(table);
vctx.table = table;

// put the current table on stack
VisitorContext vctx = new VisitorContext();
vctx.alias = alias;
vctx.selectClause = select;

Expand All @@ -205,9 +245,17 @@ public void startVisitRootObject(Field rootField, GraphQLFieldDefinition rootDef
public void endVisitRootObject(Field rootField, GraphQLFieldDefinition rootDefinition, GraphQLObjectType type) {
VisitorContext vctx = this.stack.peek();

// add table
vctx.selectClause.from(table(vctx.table.name).as(vctx.table.alias));

// add orderby
List<String> identityColumns = getIdentityColumns(type);
addOrderBy(vctx, identityColumns);
if (vctx.orderby == null) {
List<String> identityColumns = getIdentityColumns(type);
List<org.jooq.Field<?>> orderby = buildOrderBy(vctx.alias, identityColumns);
vctx.selectClause.orderBy(orderby);
} else {
vctx.selectClause.orderBy(vctx.orderby);
}

// add where
if (vctx.condition != null) {
Expand All @@ -219,6 +267,16 @@ public void endVisitRootObject(Field rootField, GraphQLFieldDefinition rootDefin
projected.add(v.as(fieldName(vctx.selectedFields.get(k))));
});
vctx.selectClause.select(projected);

// add limit & offset
if (vctx.page != null) {
if (vctx.page.limit != null) {
vctx.selectClause.limit(vctx.page.limit.intValue());
}
if (vctx.page.offset != null) {
vctx.selectClause.offset(vctx.page.offset.intValue());
}
}
}

private String alias(int i) {
Expand All @@ -241,7 +299,7 @@ public static List<String> getIdentityColumns(GraphQLObjectType type) {
return names;
}

private Table<Record> buildTable(GraphQLFieldDefinition definition, String alias) {
private AliasedTable buildTable(GraphQLFieldDefinition definition, String alias) {
SQLDirective parentDirective = null;
if (definition.getType() instanceof GraphQLModifiedType) {
GraphQLObjectType type = (GraphQLObjectType)((GraphQLModifiedType)definition.getType()).getWrappedType();
Expand All @@ -252,7 +310,7 @@ private Table<Record> buildTable(GraphQLFieldDefinition definition, String alias
}

// Build the main table
Table<Record> table = table(parentDirective.getTableName()).as(alias);
AliasedTable table = new AliasedTable(parentDirective.getTableName(), alias);
return table;
}

Expand All @@ -271,11 +329,27 @@ public void visitArgument(Field field, GraphQLFieldDefinition definition, GraphQ
SQLFilterBuilder filterBuilder = new SQLFilterBuilder(vctx.alias);

if(argName.equals("page")) {
//TODO : Walk through page results
Page p = new Page();
ObjectValue v = (ObjectValue)argValue;
for (ObjectField of: v.getObjectFields()) {
if (of.getName().equals("limit")) {
p.limit = ((IntValue)of.getValue()).getValue();
} else if (of.getName().equals("offset")) {
p.offset = ((IntValue)of.getValue()).getValue();
}
}
vctx.page = p;
} else if (argName.equals("orderBy")) {
// handle orderBy
} else if(argName.equals("filter")) {
LOGGER.debug("Walk through filter results");
FilterScanner<Condition> filterScanner = new FilterScanner<>(filterBuilder);
vctx.condition = filterScanner.scan((ObjectValue)argValue, Clause.and).condition;
Condition condition = filterScanner.scan((ObjectValue)argValue, Clause.and).condition;
if (vctx.condition == null) {
vctx.condition = condition;
} else {
vctx.condition = vctx.condition.and(condition);
}
} else {
Condition condition = filterBuilder.buildCondition(argName, "eq", argValue);
if (vctx.condition == null) {
Expand Down
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