entc/gen: generate sql builders with dialect option

Summary: Pull Request resolved: https://github.com/facebookincubator/ent/pull/130

Reviewed By: alexsn

Differential Revision: D18164397

fbshipit-source-id: 2858d69d3ff85c06b51382c01c3d4369ee2c3bdb

entc/gen/template/dialect/sql/create.tmpl

@@ -10,16 +10,15 @@ in the LICENSE file in the root directory of this source tree.
 
 func ({{ $receiver }} *{{ $builder }}) sqlSave(ctx context.Context) (*{{ $.Name }}, error) {
 	var (
-		res sql.Result
+		{{ with $.Edges }}res sql.Result{{ end }}
+		builder = sql.Dialect({{ $receiver }}.driver.Dialect())
 		{{ $.Receiver }} = &{{ $.Name }}{config: {{ $receiver }}.config}
 	)
 	tx, err := {{ $receiver }}.driver.Tx(ctx)
 	if err != nil {
 		return nil, err
 	}
-	builder := sql.Dialect({{ $receiver }}.driver.Dialect()).
-		Insert({{ $.Package }}.Table).
-		Default()
+	insert := builder.Insert({{ $.Package }}.Table).Default()
 	{{- range $_, $f := $.Fields }}
 		if value := {{ $receiver }}.{{- $f.BuilderField }}; value != nil {
 			{{- if $f.IsJSON }}
@@ -27,18 +26,14 @@ func ({{ $receiver }} *{{ $builder }}) sqlSave(ctx context.Context) (*{{ $.Name
 				if err != nil {
 					return nil, err
 				}
-				builder.Set({{ $.Package }}.{{ $f.Constant }}, buf)
+				insert.Set({{ $.Package }}.{{ $f.Constant }}, buf)
 			{{- else }}
-				builder.Set({{ $.Package }}.{{ $f.Constant }}, *value)
+			insert.Set({{ $.Package }}.{{ $f.Constant }}, *value)
 			{{- end }}
 			{{ $.Receiver }}.{{ $f.StructField }} = {{ if not $f.Nillable }}*{{ end }}value
 		}
 	{{- end }}
-	query, args := builder.Query()
-	if err := tx.Exec(ctx, query, args, &res); err != nil {
-		return nil, rollback(tx, err)
-	}
-	id, err := res.LastInsertId()
+	id, err := insertLastID(ctx, tx, insert.Returning({{ $.Package }}.{{ $.ID.Constant }}))
 	if err != nil {
 		return nil, rollback(tx, err)
 	}
@@ -48,13 +43,13 @@ func ({{ $receiver }} *{{ $builder }}) sqlSave(ctx context.Context) (*{{ $.Name
 			{{- if and $e.Unique $e.SelfRef }}{{/* O2O with self reference */}}
 				for eid := range {{ $receiver }}.{{ $e.BuilderField }} {
 					{{- template "dialect/sql/create/convertid" $e -}}
-					query, args := sql.Update({{ $.Package }}.{{ $e.TableConstant }}).
+					query, args := builder.Update({{ $.Package }}.{{ $e.TableConstant }}).
 							Set({{ $.Package }}.{{ $e.ColumnConstant }}, eid).
 							Where(sql.EQ({{ $.Package }}.{{ $.ID.Constant }}, id)).Query()
 					if err := tx.Exec(ctx, query, args, &res); err != nil {
 						return nil, rollback(tx, err)
 					}
-					query, args = sql.Update({{ $.Package }}.{{ $e.TableConstant }}).
+					query, args = builder.Update({{ $.Package }}.{{ $e.TableConstant }}).
 							Set({{ $.Package }}.{{ $e.ColumnConstant }}, id).
 							Where(sql.EQ({{ $e.Type.Package }}.{{ $e.Type.ID.Constant }}, eid).And().IsNull({{ $.Package }}.{{ $e.ColumnConstant }})).Query()
 					if err := tx.Exec(ctx, query, args, &res); err != nil {
@@ -72,7 +67,7 @@ func ({{ $receiver }} *{{ $builder }}) sqlSave(ctx context.Context) (*{{ $.Name
 				for eid := range {{ $receiver }}.{{ $e.BuilderField }} {
 					{{- template "dialect/sql/create/convertid" $e -}}
 					{{ $a := 0 }}{{ $b := 1 }}{{- if $e.IsInverse }}{{ $a = 1 }}{{ $b = 0 }}{{ end }}
-					query, args := sql.Insert({{ $.Package }}.{{ $e.TableConstant }}).
+					query, args := builder.Insert({{ $.Package }}.{{ $e.TableConstant }}).
 							Columns({{ $.Package }}.{{ $e.PKConstant }}[{{ $a }}], {{ $.Package }}.{{ $e.PKConstant }}[{{ $b }}]).
 							Values(id, eid).
 							{{- if $e.SelfRef }}{{/* self-ref creates the edges in both ways. */}}
@@ -86,7 +81,7 @@ func ({{ $receiver }} *{{ $builder }}) sqlSave(ctx context.Context) (*{{ $.Name
 			{{- else if $e.M2O }}
 				for eid := range {{ $receiver }}.{{ $e.BuilderField }} {
 					{{- template "dialect/sql/create/convertid" $e -}}
-					query, args := sql.Update({{ $.Package }}.{{ $e.TableConstant }}).
+					query, args := builder.Update({{ $.Package }}.{{ $e.TableConstant }}).
 						Set({{ $.Package }}.{{ $e.ColumnConstant }}, eid).
 						Where(sql.EQ({{ $.Package }}.{{ $.ID.Constant }}, id)).
 						Query()
@@ -100,7 +95,7 @@ func ({{ $receiver }} *{{ $builder }}) sqlSave(ctx context.Context) (*{{ $.Name
 					{{- template "dialect/sql/create/convertid" $e -}}
 					p.Or().EQ({{ $e.Type.Package }}.{{ $e.Type.ID.Constant }}, eid)
 				}
-				query, args := sql.Update({{ $.Package }}.{{ $e.TableConstant }}).
+				query, args := builder.Update({{ $.Package }}.{{ $e.TableConstant }}).
 					Set({{ $.Package }}.{{ $e.ColumnConstant }}, id).
 					Where(sql.And(p, sql.IsNull({{ $.Package }}.{{ $e.ColumnConstant }}))).
 					Query()
@@ -124,12 +119,12 @@ func ({{ $receiver }} *{{ $builder }}) sqlSave(ctx context.Context) (*{{ $.Name
 					eid := keys({{ $receiver }}.{{ $e.BuilderField }})[0]
 				{{- end }}
 				{{- if $e.IsInverse }}
-					query, args := sql.Update({{ $.Package }}.{{ $e.TableConstant }}).
+					query, args := builder.Update({{ $.Package }}.{{ $e.TableConstant }}).
 						Set({{ $.Package }}.{{ $e.ColumnConstant }}, eid).
 						Where(sql.EQ({{ $.Package }}.{{ $.ID.Constant }}, id).And().IsNull({{ $.Package }}.{{ $e.ColumnConstant }})).
 						Query()
 				{{- else }}
-					query, args := sql.Update({{ $.Package }}.{{ $e.TableConstant }}).
+					query, args := builder.Update({{ $.Package }}.{{ $e.TableConstant }}).
 						Set({{ $.Package }}.{{ $e.ColumnConstant }}, id).
 						Where(sql.EQ({{ $e.Type.Package }}.{{ $e.Type.ID.Constant }}, eid).And().IsNull({{ $.Package }}.{{ $e.ColumnConstant }})).
 						Query()

entc/gen/template/dialect/sql/delete.tmpl

@@ -9,12 +9,15 @@ in the LICENSE file in the root directory of this source tree.
 {{ $receiver := receiver $builder }}
 
 func ({{ $receiver}} *{{ $builder }}) sqlExec(ctx context.Context) (int, error) {
-	var res sql.Result
-	selector := sql.Select().From(sql.Table({{ $.Package }}.Table))
+	var (
+		res sql.Result
+		builder = sql.Dialect({{ $receiver }}.driver.Dialect())
+	)
+	selector := builder.Select().From(sql.Table({{ $.Package }}.Table))
 	for _, p := range {{ $receiver }}.predicates {
 		p(selector)
 	}
-	query, args := sql.Delete({{ $.Package }}.Table).FromSelect(selector).Query()
+	query, args := builder.Delete({{ $.Package }}.Table).FromSelect(selector).Query()
 	if err := {{ $receiver }}.driver.Exec(ctx, query, args, &res); err != nil {
 		return 0, err
 	}

entc/gen/template/dialect/sql/errors.tmpl

@@ -4,12 +4,22 @@ This source code is licensed under the Apache 2.0 license found
 in the LICENSE file in the root directory of this source tree.
 */}}
 
-{{/* custom errors and errors handlers from sql dialects */}}
+{{/* custom errors and errors handlers for sql dialects */}}
 {{ define "dialect/sql/errors" }}
 func isSQLConstraintError(err error) (*ErrConstraintFailed, bool) {
-	// Error number 1062 is ER_DUP_ENTRY in mysql, and "UNIQUE constraint failed" is SQLite prefix.
-	if msg := err.Error(); strings.HasPrefix(msg, "Error 1062") || strings.HasPrefix(msg, "UNIQUE constraint failed") {
-		return &ErrConstraintFailed{msg, err}, true
+	var (
+		msg = err.Error()
+		// error format per dialect.
+		errors = [...]string{
+			"Error 1062",										// MySQL 1062 error (ER_DUP_ENTRY).
+			"UNIQUE constraint failed",							// SQLite.
+			"duplicate key value violates unique constraint",	// PostgreSQL.
+		}
+	)
+	for i := range errors {
+		if strings.Contains(msg, errors[i]) {
+			return &ErrConstraintFailed{msg, err}, true
+		}
 	}
 	return nil, false
 }

entc/gen/template/dialect/sql/globals.tmpl

@@ -0,0 +1,40 @@
+{{/*
+Copyright 2019-present Facebook Inc. All rights reserved.
+This source code is licensed under the Apache 2.0 license found
+in the LICENSE file in the root directory of this source tree.
+*/}}
+
+{{/* custom globals and helpers for sql dialects */}}
+{{ define "dialect/sql/globals" }}
+// insertLastID invokes the insert query on the transaction and returns the LastInsertID.
+func insertLastID(ctx context.Context, tx dialect.Tx, insert *sql.InsertBuilder) (int64, error) {
+	query, args := insert.Query()
+	// PostgreSQL does not support the LastInsertId() method of sql.Result
+	// on Exec, and should be extracted manually using the `RETURNING` clause.
+	if insert.Dialect() == dialect.Postgres {
+		rows := &sql.Rows{}
+		if err := tx.Query(ctx, query, args, rows); err != nil {
+			return 0, err
+		}
+		defer rows.Close()
+		if !rows.Next() {
+			return 0, fmt.Errorf("no rows found for query: %v", query)
+		}
+		var id int64
+		if err := rows.Scan(&id); err != nil {
+			return 0, err
+		}
+		return id, nil
+	}
+	// MySQL, SQLite, etc.
+	var res sql.Result
+	if err := tx.Exec(ctx, query, args, &res); err != nil {
+		return 0, err
+	}
+	id, err := res.LastInsertId()
+	if err != nil {
+		return 0, err
+	}
+	return id, nil
+}
+{{ end }}

entc/gen/template/dialect/sql/predicate.tmpl

@@ -64,10 +64,12 @@ in the LICENSE file in the root directory of this source tree.
 	func(s *sql.Selector) {
 		{{- if $e.M2M  }}
 			t1 := s.Table()
+			builder := sql.Dialect(s.Dialect())
 			s.Where(
 				sql.In(
 					t1.C({{ $.ID.Constant }}),
-					sql.Select({{ $e.PKConstant }}[{{ if $e.IsInverse }}1{{ else }}0{{ end }}]).From(sql.Table({{ $e.TableConstant }})),
+					builder.Select({{ $e.PKConstant }}[{{ if $e.IsInverse }}1{{ else }}0{{ end }}]).
+						From(builder.Table({{ $e.TableConstant }})),
 				),
 			)
 		{{- else if or $e.M2O (and $e.O2O $e.IsInverse) }}{{/* M2O || (O2O with inverse edge) */}}
@@ -75,11 +77,12 @@ in the LICENSE file in the root directory of this source tree.
 			s.Where(sql.NotNull(t1.C({{ $e.ColumnConstant }})))
 		{{- else }}{{/* O2M || (O2O with assoc edge) */}}
 			t1 := s.Table()
+			builder := sql.Dialect(s.Dialect())
 			s.Where(
 				sql.In(
 					t1.C({{ $.ID.Constant }}),
-					sql.Select({{ $e.ColumnConstant }}).
-						From(sql.Table({{ $e.TableConstant }})).
+					builder.Select({{ $e.ColumnConstant }}).
+						From(builder.Table({{ $e.TableConstant }})).
 						Where(sql.NotNull({{ $e.ColumnConstant }})),
 				),
 			)
@@ -92,28 +95,30 @@ in the LICENSE file in the root directory of this source tree.
 	func(s *sql.Selector) {
 		{{- if $e.M2M  }}
 			{{ $i := 1 }}{{ $j := 0 }}{{- if $e.IsInverse }}{{ $i = 0 }}{{ $j = 1 }}{{ end -}}
+			builder := sql.Dialect(s.Dialect())
 			t1 := s.Table()
-			t2 := sql.Table(
+			t2 := builder.Table(
 				{{- if ne $.Table $e.Type.Table -}}
 					{{ $e.InverseTableConstant }}
 				{{- else -}}
 					Table
 				{{- end -}}
 			)
-			t3 := sql.Table({{ $e.TableConstant }})
-			t4 := sql.Select(t3.C({{ $e.PKConstant }}[{{ $j }}])).
+			t3 := builder.Table({{ $e.TableConstant }})
+			t4 := builder.Select(t3.C({{ $e.PKConstant }}[{{ $j }}])).
 				From(t3).
 				Join(t2).
 				On(t3.C({{ $e.PKConstant }}[{{ $i }}]), t2.C({{ $e.Type.ID.Constant }}))
-			t5 := sql.Select().From(t2)
+			t5 := builder.Select().From(t2)
 			for _, p := range preds {
 				p(t5)
 			}
 			t4.FromSelect(t5)
 			s.Where(sql.In(t1.C({{ $.ID.Constant }}), t4))
 		{{- else if or $e.M2O (and $e.O2O $e.IsInverse) }}{{/* M2O || (O2O with inverse edge) */}}
+			builder := sql.Dialect(s.Dialect())
 			t1 := s.Table()
-			t2 := sql.Select({{ $e.Type.ID.Constant }}).From(sql.Table(
+			t2 := builder.Select({{ $e.Type.ID.Constant }}).From(builder.Table(
 				{{- if ne $.Table $e.Type.Table -}}
 					{{ $e.InverseTableConstant }}
 				{{- else -}}
@@ -125,8 +130,9 @@ in the LICENSE file in the root directory of this source tree.
 			}
 			s.Where(sql.In(t1.C({{ $e.ColumnConstant }}), t2))
 		{{- else }}{{/* O2M || (O2O with assoc edge) */}}
+			builder := sql.Dialect(s.Dialect())
 			t1 := s.Table()
-			t2 := sql.Select({{ $e.ColumnConstant }}).From(sql.Table({{ $e.TableConstant }}))
+			t2 := builder.Select({{ $e.ColumnConstant }}).From(builder.Table({{ $e.TableConstant }}))
 			for _, p := range preds {
 				p(t2)
 			}

entc/gen/template/dialect/sql/query.tmpl

@@ -61,8 +61,9 @@ func ({{ $receiver }} *{{ $builder }}) sqlExist(ctx context.Context) (bool, erro
 }
 
 func ({{ $receiver }} *{{ $builder }}) sqlQuery() *sql.Selector {
-	t1 := sql.Table({{ $.Package }}.Table)
-	selector := sql.Select(t1.Columns({{ $.Package }}.Columns...)...).From(t1)
+	builder := sql.Dialect({{ $receiver }}.driver.Dialect())
+	t1 := builder.Table({{ $.Package }}.Table)
+	selector := builder.Select(t1.Columns({{ $.Package }}.Columns...)...).From(t1)
 	if {{ $receiver }}.sql != nil {
 		selector = {{ $receiver }}.sql
 		selector.Select(selector.Columns({{ $.Package }}.Columns...)...)
@@ -90,33 +91,34 @@ func ({{ $receiver }} *{{ $builder }}) sqlQuery() *sql.Selector {
 	{{- $e := $.Scope.Edge }} {{/* the edge we need to genegrate the path to. */}}
 	{{- $receiver := $.Scope.Receiver }}
 
+	builder := sql.Dialect({{ $receiver }}.driver.Dialect())
 	{{- if $e.M2M }}
 		{{ $i := 1 }}{{ $j := 0 }}{{- if $e.IsInverse }}{{ $i = 0 }}{{ $j = 1 }}{{ end -}}
-		t1 := sql.Table({{ $e.Type.Package }}.Table)
+		t1 := builder.Table({{ $e.Type.Package }}.Table)
 		t2 := {{ $receiver }}.sqlQuery()
 		t2.Select(t2.C({{ $.Package }}.{{ $.ID.Constant }}))
-		t3 := sql.Table({{ $.Package }}.{{ $e.TableConstant }})
-		t4 := sql.Select(t3.C({{ $.Package }}.{{ $e.PKConstant }}[{{ $i }}])).
+		t3 := builder.Table({{ $.Package }}.{{ $e.TableConstant }})
+		t4 := builder.Select(t3.C({{ $.Package }}.{{ $e.PKConstant }}[{{ $i }}])).
 				From(t3).
 				Join(t2).
 				On(t3.C({{ $.Package }}.{{ $e.PKConstant }}[{{ $j }}]), t2.C({{ $.Package }}.{{ $.ID.Constant }}))
-		query.sql = sql.Select().
+		query.sql = builder.Select().
 			From(t1).
 			Join(t4).
 			On(t1.C({{ $e.Type.Package }}.{{ $e.Type.ID.Constant }}), t4.C({{ $.Package }}.{{ $e.PKConstant }}[{{ $i }}]))
 	{{- else if or $e.M2O (and $e.O2O $e.IsInverse) }}{{/* M2O || (O2O with inverse edge) */}}
-		t1 := sql.Table({{ $e.Type.Package }}.Table)
+		t1 := builder.Table({{ $e.Type.Package }}.Table)
 		t2 := {{ $receiver }}.sqlQuery()
 		t2.Select(t2.C({{ $.Package }}.{{ $e.ColumnConstant }}))
-		query.sql = sql.Select(t1.Columns({{ $e.Type.Package }}.Columns...)...).
+		query.sql = builder.Select(t1.Columns({{ $e.Type.Package }}.Columns...)...).
 			From(t1).
 			Join(t2).
 			On(t1.C({{ $e.Type.Package }}.{{ $e.Type.ID.Constant }}), t2.C({{ $.Package }}.{{ $e.ColumnConstant }}))
 	{{- else }}{{/* O2M || (O2O with assoc edge) */}}
-		t1 := sql.Table({{ $e.Type.Package }}.Table)
+		t1 := builder.Table({{ $e.Type.Package }}.Table)
 		t2 := {{ $receiver }}.sqlQuery()
 		t2.Select(t2.C({{ $.Package }}.{{ $.ID.Constant }}))
-		query.sql = sql.Select().
+		query.sql = builder.Select().
 			From(t1).
 			Join(t2).
 			On(t1.C({{ $.Package }}.{{ $e.ColumnConstant }}), t2.C({{ $.Package }}.{{ $.ID.Constant }}))
@@ -130,28 +132,29 @@ func ({{ $receiver }} *{{ $builder }}) sqlQuery() *sql.Selector {
 	{{- $receiver := $.Scope.Receiver -}}
 
 	id := {{ $receiver }}.{{- if $n.ID.IsString }}id(){{ else }}ID{{ end }}
+	builder := sql.Dialect({{ $receiver }}.driver.Dialect())
 	{{- if $e.M2M  }}
 		{{ $i := 1 }}{{ $j := 0 }}{{- if $e.IsInverse }}{{ $i = 0 }}{{ $j = 1 }}{{ end -}}
-		t1 := sql.Table({{ $e.Type.Package }}.Table)
-		t2 := sql.Table({{ $n.Package }}.Table)
-		t3 := sql.Table({{ $n.Package }}.{{ $e.TableConstant }})
-		t4 := sql.Select(t3.C({{ $n.Package }}.{{ $e.PKConstant }}[{{ $i }}])).
+		t1 := builder.Table({{ $e.Type.Package }}.Table)
+		t2 := builder.Table({{ $n.Package }}.Table)
+		t3 := builder.Table({{ $n.Package }}.{{ $e.TableConstant }})
+		t4 := builder.Select(t3.C({{ $n.Package }}.{{ $e.PKConstant }}[{{ $i }}])).
 				From(t3).
 				Join(t2).
 				On(t3.C({{ $n.Package }}.{{ $e.PKConstant }}[{{ $j }}]), t2.C({{ $n.Package }}.{{ $n.ID.Constant }})).
 				Where(sql.EQ(t2.C({{ $n.Package }}.{{ $n.ID.Constant }}), id))
-		query.sql = sql.Select().
+		query.sql = builder.Select().
 			From(t1).
 			Join(t4).
 			On(t1.C({{ $e.Type.Package }}.{{ $e.Type.ID.Constant }}), t4.C({{ $n.Package }}.{{ $e.PKConstant }}[{{ $i }}]))
 	{{- else if or $e.M2O (and $e.O2O $e.IsInverse) }}{{/* M2O || (O2O with inverse edge) */}}
-		t1 := sql.Table({{ $e.Type.Package }}.Table)
-		t2 := sql.Select({{ $n.Package }}.{{ $e.ColumnConstant }}).
-			From(sql.Table({{ $n.Package }}.{{ $e.TableConstant }})).
+		t1 := builder.Table({{ $e.Type.Package }}.Table)
+		t2 := builder.Select({{ $n.Package }}.{{ $e.ColumnConstant }}).
+			From(builder.Table({{ $n.Package }}.{{ $e.TableConstant }})).
 			Where(sql.EQ({{ $n.Package }}.{{ $n.ID.Constant }}, id))
-		query.sql = sql.Select().From(t1).Join(t2).On(t1.C({{ $e.Type.Package }}.{{ $e.Type.ID.Constant }}), t2.C({{ $n.Package }}.{{ $e.ColumnConstant }}))
+		query.sql = builder.Select().From(t1).Join(t2).On(t1.C({{ $e.Type.Package }}.{{ $e.Type.ID.Constant }}), t2.C({{ $n.Package }}.{{ $e.ColumnConstant }}))
 	{{- else }}{{/* O2M || (O2O with assoc edge) */}}
-		query.sql = sql.Select().From(sql.Table({{ $e.Type.Package }}.Table)).
+		query.sql = builder.Select().From(builder.Table({{ $e.Type.Package }}.Table)).
 			Where(sql.EQ({{ $n.Package }}.{{ $e.ColumnConstant }}, id))
 	{{- end }}
 {{ end }}

entc/gen/template/dialect/sql/select.tmpl

@@ -21,6 +21,7 @@ func ({{ $receiver }} *{{ $builder }}) sqlScan(ctx context.Context, v interface{
 
 func ({{ $receiver }} *{{ $builder }}) sqlQuery() sql.Querier {
 	view := "{{ $.Package }}_view"
-	return sql.Select({{ $receiver }}.fields...).From({{ $receiver }}.sql.As(view))
+	return sql.Dialect({{ $receiver }}.driver.Dialect()).
+		Select({{ $receiver }}.fields...).From({{ $receiver }}.sql.As(view))
 }
 {{ end }}

entc/gen/template/dialect/sql/update.tmpl

@@ -13,7 +13,10 @@ in the LICENSE file in the root directory of this source tree.
 {{- $ret := "n" }}{{ if $one }}{{ $ret = $.Receiver }}{{ end }}
 
 func ({{ $receiver }} *{{ $builder }}) sqlSave(ctx context.Context) ({{ $ret }} {{ if $one }}*{{ $.Name }}{{ else }}int{{ end }}, err error) {
-	selector := sql.Select({{ $.Package }}.{{ if $one }}Columns...{{ else }}{{ $.ID.Constant }}{{ end }}).From(sql.Table({{ $.Package }}.Table))
+	var (
+		builder = sql.Dialect({{ $receiver }}.driver.Dialect())
+		selector = builder.Select({{ $.Package }}.{{ if $one }}Columns...{{ else }}{{ $.ID.Constant }}{{ end }}).From(builder.Table({{ $.Package }}.Table))
+	)
 	{{- if $one }}
 		{{ $.Package }}.ID({{ $receiver }}.id)(selector)
 	{{- else }}
@@ -63,7 +66,7 @@ func ({{ $receiver }} *{{ $builder }}) sqlSave(ctx context.Context) ({{ $ret }}
 	{{- if $.Fields }}
 		var (
 			res sql.Result
-			builder = sql.Update({{ $.Package }}.Table).Where(sql.InInts({{ $.Package }}.{{ $.ID.Constant }}, ids...))
+			updater = builder.Update({{ $.Package }}.Table).Where(sql.InInts({{ $.Package }}.{{ $.ID.Constant }}, ids...))
 		)
 		{{- range $_, $f := $.Fields }}
 			{{- if or (not $f.Immutable) $f.UpdateDefault }}
@@ -73,9 +76,9 @@ func ({{ $receiver }} *{{ $builder }}) sqlSave(ctx context.Context) ({{ $ret }}
 						if err != nil {
 							return {{ $zero }}, err
 						}
-						builder.Set({{ $.Package }}.{{ $f.Constant }}, buf)
+						updater.Set({{ $.Package }}.{{ $f.Constant }}, buf)
 					{{- else }}
-						builder.Set({{ $.Package }}.{{ $f.Constant }}, *value)
+						updater.Set({{ $.Package }}.{{ $f.Constant }}, *value)
 					{{- end }}
 					{{- if $one }}
 						{{ $.Receiver }}.{{ $f.StructField }} = {{ if not $f.Nillable }}*{{ end }}value
@@ -83,7 +86,7 @@ func ({{ $receiver }} *{{ $builder }}) sqlSave(ctx context.Context) ({{ $ret }}
 				}
 				{{- if $f.Type.Numeric }}
 					if value := {{ $receiver }}.add{{ $f.BuilderField }}; value != nil {
-						builder.Add({{ $.Package }}.{{ $f.Constant }}, *value)
+						updater.Add({{ $.Package }}.{{ $f.Constant }}, *value)
 						{{- if $one }}
 							{{- if $f.Nillable }}
 								if {{ $.Receiver }}.{{ $f.StructField }} != nil {
@@ -108,12 +111,12 @@ func ({{ $receiver }} *{{ $builder }}) sqlSave(ctx context.Context) ({{ $ret }}
 							{{ $.Receiver }}.{{ $f.StructField }} = value
 						{{- end }}
 					{{- end }}
-					builder.SetNull({{ $.Package }}.{{ $f.Constant }})
+					updater.SetNull({{ $.Package }}.{{ $f.Constant }})
 				}
 			{{- end }}
 		{{- end }}
-		if !builder.Empty() {
-			query, args := builder.Query()
+		if !updater.Empty() {
+			query, args := updater.Query()
 			if err := tx.Exec(ctx, query, args, &res); err != nil {
 				return {{ $zero }}, rollback(tx, err)
 			}
@@ -130,7 +133,7 @@ func ({{ $receiver }} *{{ $builder }}) sqlSave(ctx context.Context) ({{ $ret }}
 					{{- template "dialect/sql/update/convertid" $e -}}
 					eids = append(eids, eid)
 				}
-				query, args := sql.Delete({{ $.Package }}.{{ $e.TableConstant }}).
+				query, args := builder.Delete({{ $.Package }}.{{ $e.TableConstant }}).
 					Where(sql.InInts({{ $.Package }}.{{ $e.PKConstant }}[{{ $a }}], ids...)).
 					Where(sql.InInts({{ $.Package }}.{{ $e.PKConstant }}[{{ $b }}], eids...)).
 					Query()
@@ -138,7 +141,7 @@ func ({{ $receiver }} *{{ $builder }}) sqlSave(ctx context.Context) ({{ $ret }}
 					return {{ $zero }}, rollback(tx, err)
 				}
 				{{- if $e.SelfRef }}{{/* M2M with self reference */}}{{/* TODO: use OR in the case above. */}}
-					query, args = sql.Delete({{ $.Package }}.{{ $e.TableConstant }}).
+					query, args = builder.Delete({{ $.Package }}.{{ $e.TableConstant }}).
 						Where(sql.InInts({{ $.Package }}.{{ $e.PKConstant }}[{{ $b }}], ids...)).
 						Where(sql.InInts({{ $.Package }}.{{ $e.PKConstant }}[{{ $a }}], eids...)).
 						Query()
@@ -154,7 +157,7 @@ func ({{ $receiver }} *{{ $builder }}) sqlSave(ctx context.Context) ({{ $ret }}
 					{{- template "dialect/sql/update/convertid" $e -}}
 					eids = append(eids, eid)
 				}
-				query, args := sql.Update({{ $.Package }}.{{ $e.TableConstant }}).
+				query, args := builder.Update({{ $.Package }}.{{ $e.TableConstant }}).
 					SetNull({{ $.Package }}.{{ $e.ColumnConstant }}).
 					Where(sql.InInts({{ $.Package }}.{{ $e.ColumnConstant }}, ids...)).
 					Where(sql.InInts({{ $e.Type.Package }}.{{ $e.Type.ID.Constant }}, eids...)).
@@ -165,7 +168,7 @@ func ({{ $receiver }} *{{ $builder }}) sqlSave(ctx context.Context) ({{ $ret }}
 			}
 		{{- else }}{{/* O2O or M2O */}}
 			if {{ $receiver }}.cleared{{ $e.StructField }} {
-				query, args := sql.Update({{ $.Package }}.{{ $e.TableConstant }}).
+				query, args := builder.Update({{ $.Package }}.{{ $e.TableConstant }}).
 					SetNull({{ $.Package }}.{{ $e.ColumnConstant }}).
 					Where(sql.InInts({{ $e.Type.Package }}.{{ $e.Type.ID.Constant }}, ids...)).
 					Query()
@@ -173,7 +176,7 @@ func ({{ $receiver }} *{{ $builder }}) sqlSave(ctx context.Context) ({{ $ret }}
 					return {{ $zero }}, rollback(tx, err)
 				}
 				{{- if $e.SelfRef }}{{/* O2O with self reference */}}
-					query, args = sql.Update({{ $.Package }}.{{ $e.TableConstant }}).
+					query, args = builder.Update({{ $.Package }}.{{ $e.TableConstant }}).
 						SetNull({{ $.Package }}.{{ $e.ColumnConstant }}).
 						Where(sql.InInts({{ $.Package }}.{{ $e.ColumnConstant }}, ids...)).
 						Query()
@@ -190,13 +193,13 @@ func ({{ $receiver }} *{{ $builder }}) sqlSave(ctx context.Context) ({{ $ret }}
 				}
 				for eid := range {{ $receiver }}.{{ $e.BuilderField }} {
 					{{- template "dialect/sql/update/convertid" $e -}}
-					query, args := sql.Update({{ $.Package }}.{{ $e.TableConstant }}).
+					query, args := builder.Update({{ $.Package }}.{{ $e.TableConstant }}).
 							Set({{ $.Package }}.{{ $e.ColumnConstant }}, eid).
 							Where(sql.EQ({{ $.Package }}.{{ $.ID.Constant }}, ids[0])).Query()
 					if err := tx.Exec(ctx, query, args, &res); err != nil {
 						return {{ $zero }}, rollback(tx, err)
 					}
-					query, args = sql.Update({{ $.Package }}.{{ $e.TableConstant }}).
+					query, args = builder.Update({{ $.Package }}.{{ $e.TableConstant }}).
 							Set({{ $.Package }}.{{ $e.ColumnConstant }}, ids[0]).
 							Where(sql.EQ({{ $e.Type.Package }}.{{ $e.Type.ID.Constant }}, eid).And().IsNull({{ $.Package }}.{{ $e.ColumnConstant }})).Query()
 					if err := tx.Exec(ctx, query, args, &res); err != nil {
@@ -219,7 +222,7 @@ func ({{ $receiver }} *{{ $builder }}) sqlSave(ctx context.Context) ({{ $ret }}
 					}
 				}
 				{{- $a := 0 }}{{ $b := 1 }}{{ if $e.IsInverse }}{{ $a = 1 }}{{ $b = 0 }}{{ end }}
-				builder := sql.Insert({{ $.Package }}.{{ $e.TableConstant }}).
+				builder := builder.Insert({{ $.Package }}.{{ $e.TableConstant }}).
 					Columns({{ $.Package }}.{{ $e.PKConstant }}[{{ $a }}], {{ $.Package }}.{{ $e.PKConstant }}[{{ $b }}])
 				for _, v := range values {
 					builder.Values(v[0], v[1])
@@ -231,7 +234,7 @@ func ({{ $receiver }} *{{ $builder }}) sqlSave(ctx context.Context) ({{ $ret }}
 			{{- else if $e.M2O }}
 				for eid := range {{ $receiver }}.{{ $e.BuilderField }} {
 					{{- template "dialect/sql/update/convertid" $e -}}
-					query, args := sql.Update({{ $.Package }}.{{ $e.TableConstant }}).
+					query, args := builder.Update({{ $.Package }}.{{ $e.TableConstant }}).
 						Set({{ $.Package }}.{{ $e.ColumnConstant }}, eid).
 						Where(sql.InInts({{ $.Package }}.{{ $.ID.Constant }}, ids...)).
 						Query()
@@ -246,7 +249,7 @@ func ({{ $receiver }} *{{ $builder }}) sqlSave(ctx context.Context) ({{ $ret }}
 						{{- template "dialect/sql/update/convertid" $e -}}
 						p.Or().EQ({{ $e.Type.Package }}.{{ $e.Type.ID.Constant }}, eid)
 					}
-					query, args := sql.Update({{ $.Package }}.{{ $e.TableConstant }}).
+					query, args := builder.Update({{ $.Package }}.{{ $e.TableConstant }}).
 						Set({{ $.Package }}.{{ $e.ColumnConstant }}, id).
 						Where(sql.And(p, sql.IsNull({{ $.Package }}.{{ $e.ColumnConstant }}))).
 						Query()
@@ -272,12 +275,12 @@ func ({{ $receiver }} *{{ $builder }}) sqlSave(ctx context.Context) ({{ $ret }}
 						eid := keys({{ $receiver }}.{{ $e.BuilderField }})[0]
 					{{- end }}
 					{{- if $e.IsInverse }}
-						query, args := sql.Update({{ $.Package }}.{{ $e.TableConstant }}).
+						query, args := builder.Update({{ $.Package }}.{{ $e.TableConstant }}).
 							Set({{ $.Package }}.{{ $e.ColumnConstant }}, eid).
 							Where(sql.EQ({{ $.Package }}.{{ $.ID.Constant }}, id).And().IsNull({{ $.Package }}.{{ $e.ColumnConstant }})).
 							Query()
 					{{- else }}
-						query, args := sql.Update({{ $.Package }}.{{ $e.TableConstant }}).
+						query, args := builder.Update({{ $.Package }}.{{ $e.TableConstant }}).
 							Set({{ $.Package }}.{{ $e.ColumnConstant }}, id).
 							Where(sql.EQ({{ $e.Type.Package }}.{{ $e.Type.ID.Constant }}, eid).And().IsNull({{ $.Package }}.{{ $e.ColumnConstant }})).
 							Query()