Merge pull request #339 from upper/issue-338

Fix DISTINCT and provide examples for DISTINCT ON

internal/sqladapter/exql/default.go

@@ -25,47 +25,50 @@ const (
 	defaultSortByColumnLayout  = `{{.Column}} {{.Order}}`
 
 	defaultOrderByLayout = `
-		{{if .SortColumns}}
-			ORDER BY {{.SortColumns}}
-		{{end}}
-	`
+    {{if .SortColumns}}
+      ORDER BY {{.SortColumns}}
+    {{end}}
+  `
 
 	defaultWhereLayout = `
-		{{if .Conds}}
-			WHERE {{.Conds}}
-		{{end}}
-	`
+    {{if .Conds}}
+      WHERE {{.Conds}}
+    {{end}}
+  `
 
 	defaultUsingLayout = `
-		{{if .Columns}}
-			USING ({{.Columns}})
-		{{end}}
-	`
+    {{if .Columns}}
+      USING ({{.Columns}})
+    {{end}}
+  `
 
 	defaultJoinLayout = `
-		{{if .Table}}
-			{{ if .On }}
-				{{.Type}} JOIN {{.Table}}
-				{{.On}}
-			{{ else if .Using }}
-				{{.Type}} JOIN {{.Table}}
-				{{.Using}}
-			{{ else if .Type | eq "CROSS" }}
-				{{.Type}} JOIN {{.Table}}
-			{{else}}
-				NATURAL {{.Type}} JOIN {{.Table}}
-			{{end}}
-		{{end}}
-	`
+    {{if .Table}}
+      {{ if .On }}
+        {{.Type}} JOIN {{.Table}}
+        {{.On}}
+      {{ else if .Using }}
+        {{.Type}} JOIN {{.Table}}
+        {{.Using}}
+      {{ else if .Type | eq "CROSS" }}
+        {{.Type}} JOIN {{.Table}}
+      {{else}}
+        NATURAL {{.Type}} JOIN {{.Table}}
+      {{end}}
+    {{end}}
+  `
 
 	defaultOnLayout = `
-		{{if .Conds}}
-			ON {{.Conds}}
-		{{end}}
-	`
+    {{if .Conds}}
+      ON {{.Conds}}
+    {{end}}
+  `
 
 	defaultSelectLayout = `
     SELECT
+      {{if .Distinct}}
+        DISTINCT
+      {{end}}
 
       {{if .Columns}}
         {{.Columns}}
@@ -92,7 +95,7 @@ const (
       {{if .Offset}}
         OFFSET {{.Offset}}
       {{end}}
-	`
+  `
 	defaultDeleteLayout = `
     DELETE
       FROM {{.Table}}
@@ -103,92 +106,92 @@ const (
     {{if .Offset}}
       OFFSET {{.Offset}}
     {{end}}
-	`
+  `
 	defaultUpdateLayout = `
-		UPDATE
-			{{.Table}}
-		SET {{.ColumnValues}}
-			{{ .Where }}
-	`
+    UPDATE
+      {{.Table}}
+    SET {{.ColumnValues}}
+      {{ .Where }}
+  `
 
 	defaultCountLayout = `
-		SELECT
-			COUNT(1) AS _t
-		FROM {{.Table}}
-			{{.Where}}
+    SELECT
+      COUNT(1) AS _t
+    FROM {{.Table}}
+      {{.Where}}
 
-			{{if .Limit}}
-				LIMIT {{.Limit}}
-			{{end}}
+      {{if .Limit}}
+        LIMIT {{.Limit}}
+      {{end}}
 
-			{{if .Offset}}
-				OFFSET {{.Offset}}
-			{{end}}
-	`
+      {{if .Offset}}
+        OFFSET {{.Offset}}
+      {{end}}
+  `
 
 	defaultInsertLayout = `
     INSERT INTO {{.Table}}
       {{if .Columns }}({{.Columns}}){{end}}
     VALUES
       {{.Values}}
-		{{if .Returning}}
-			RETURNING {{.Returning}}
-		{{end}}
-	`
+    {{if .Returning}}
+      RETURNING {{.Returning}}
+    {{end}}
+  `
 
 	defaultTruncateLayout = `
-		TRUNCATE TABLE {{.Table}}
-	`
+    TRUNCATE TABLE {{.Table}}
+  `
 
 	defaultDropDatabaseLayout = `
-		DROP DATABASE {{.Database}}
-	`
+    DROP DATABASE {{.Database}}
+  `
 
 	defaultDropTableLayout = `
-		DROP TABLE {{.Table}}
-	`
+    DROP TABLE {{.Table}}
+  `
 
 	defaultGroupByColumnLayout = `{{.Column}}`
 
 	defaultGroupByLayout = `
-		{{if .GroupColumns}}
-			GROUP BY {{.GroupColumns}}
-		{{end}}
-	`
+    {{if .GroupColumns}}
+      GROUP BY {{.GroupColumns}}
+    {{end}}
+  `
 )
 
 var defaultTemplate = &Template{
-	ColumnSeparator:     defaultColumnSeparator,
-	IdentifierSeparator: defaultIdentifierSeparator,
-	IdentifierQuote:     defaultIdentifierQuote,
-	ValueSeparator:      defaultValueSeparator,
-	ValueQuote:          defaultValueQuote,
 	AndKeyword:          defaultAndKeyword,
-	OrKeyword:           defaultOrKeyword,
-	NotKeyword:          defaultNotKeyword,
-	DescKeyword:         defaultDescKeyword,
 	AscKeyword:          defaultAscKeyword,
-	DefaultOperator:     defaultDefaultOperator,
 	AssignmentOperator:  defaultAssignmentOperator,
 	ClauseGroup:         defaultClauseGroup,
 	ClauseOperator:      defaultClauseOperator,
-	ColumnValue:         defaultColumnValue,
-	TableAliasLayout:    defaultTableAliasLayout,
 	ColumnAliasLayout:   defaultColumnAliasLayout,
-	SortByColumnLayout:  defaultSortByColumnLayout,
-	WhereLayout:         defaultWhereLayout,
-	OnLayout:            defaultOnLayout,
-	UsingLayout:         defaultUsingLayout,
-	JoinLayout:          defaultJoinLayout,
-	OrderByLayout:       defaultOrderByLayout,
-	InsertLayout:        defaultInsertLayout,
-	SelectLayout:        defaultSelectLayout,
-	UpdateLayout:        defaultUpdateLayout,
+	ColumnSeparator:     defaultColumnSeparator,
+	ColumnValue:         defaultColumnValue,
+	CountLayout:         defaultCountLayout,
 	DeleteLayout:        defaultDeleteLayout,
-	TruncateLayout:      defaultTruncateLayout,
+	DescKeyword:         defaultDescKeyword,
 	DropDatabaseLayout:  defaultDropDatabaseLayout,
 	DropTableLayout:     defaultDropTableLayout,
-	CountLayout:         defaultCountLayout,
 	GroupByLayout:       defaultGroupByLayout,
-	Cache:               cache.NewCache(),
+	IdentifierQuote:     defaultIdentifierQuote,
+	IdentifierSeparator: defaultIdentifierSeparator,
+	InsertLayout:        defaultInsertLayout,
+	JoinLayout:          defaultJoinLayout,
+	NotKeyword:          defaultNotKeyword,
+	OnLayout:            defaultOnLayout,
+	OrKeyword:           defaultOrKeyword,
+	OrderByLayout:       defaultOrderByLayout,
+	SelectLayout:        defaultSelectLayout,
+	SortByColumnLayout:  defaultSortByColumnLayout,
+	TableAliasLayout:    defaultTableAliasLayout,
+	TruncateLayout:      defaultTruncateLayout,
+	UpdateLayout:        defaultUpdateLayout,
+	UsingLayout:         defaultUsingLayout,
+	ValueQuote:          defaultValueQuote,
+	ValueSeparator:      defaultValueSeparator,
+	WhereLayout:         defaultWhereLayout,
+
+	Cache: cache.NewCache(),
 }

internal/sqladapter/exql/statement.go

@@ -17,6 +17,7 @@ type Statement struct {
 	ColumnValues Fragment
 	OrderBy      Fragment
 	GroupBy      Fragment
+	Distinct     bool
 	Joins        Fragment
 	Where        Fragment
 	Returning    Fragment
@@ -38,6 +39,7 @@ type statementT struct {
 	ColumnValues string
 	OrderBy      string
 	GroupBy      string
+	Distinct     bool
 	Where        string
 	Joins        string
 	Returning    string
@@ -89,6 +91,7 @@ func (s *Statement) Compile(layout *Template) (compiled string) {
 	data := statementT{
 		Table:        layout.doCompile(s.Table),
 		Database:     layout.doCompile(s.Database),
+		Distinct:     s.Distinct,
 		Limit:        s.Limit,
 		Offset:       s.Offset,
 		Columns:      layout.doCompile(s.Columns),

internal/sqladapter/exql/template.go

@@ -38,38 +38,39 @@ var (
 
 // Template is an SQL template.
 type Template struct {
-	ColumnSeparator     string
-	IdentifierSeparator string
-	IdentifierQuote     string
-	ValueSeparator      string
-	ValueQuote          string
 	AndKeyword          string
-	OrKeyword           string
-	NotKeyword          string
-	DescKeyword         string
 	AscKeyword          string
-	DefaultOperator     string
 	AssignmentOperator  string
 	ClauseGroup         string
 	ClauseOperator      string
-	ColumnValue         string
-	TableAliasLayout    string
 	ColumnAliasLayout   string
-	SortByColumnLayout  string
-	WhereLayout         string
-	OnLayout            string
-	UsingLayout         string
-	JoinLayout          string
-	OrderByLayout       string
-	InsertLayout        string
-	SelectLayout        string
-	UpdateLayout        string
+	ColumnSeparator     string
+	ColumnValue         string
+	CountLayout         string
+	DefaultOperator     string
 	DeleteLayout        string
-	TruncateLayout      string
+	DescKeyword         string
 	DropDatabaseLayout  string
 	DropTableLayout     string
-	CountLayout         string
 	GroupByLayout       string
+	IdentifierQuote     string
+	IdentifierSeparator string
+	InsertLayout        string
+	JoinLayout          string
+	NotKeyword          string
+	OnLayout            string
+	OrKeyword           string
+	OrderByLayout       string
+	SelectLayout        string
+	SortByColumnLayout  string
+	TableAliasLayout    string
+	TruncateLayout      string
+	UpdateLayout        string
+	UsingLayout         string
+	ValueQuote          string
+	ValueSeparator      string
+	WhereLayout         string
+
 	*cache.Cache
 }