Merge pull request #133 from cemremengu/insertselect

add subselect builder for insert

Author: huandu

insert.go

@@ -13,6 +13,7 @@ const (
 	insertMarkerAfterInsertInto
 	insertMarkerAfterCols
 	insertMarkerAfterValues
+	insertMarkerAfterSelect
 )
 
 // NewInsertBuilder creates a new INSERT builder.
@@ -40,6 +41,8 @@ type InsertBuilder struct {
 
 	injection *injection
 	marker    injectionMarker
+
+	sbHolder string
 }
 
 var _ Builder = new(InsertBuilder)
@@ -89,6 +92,13 @@ func (ib *InsertBuilder) Cols(col ...string) *InsertBuilder {
 	return ib
 }
 
+// Select returns a new SelectBuilder to build a SELECT statement inside the INSERT INTO.
+func (isb *InsertBuilder) Select(col ...string) *SelectBuilder {
+	sb := Select(col...)
+	isb.sbHolder = isb.args.Add(sb)
+	return sb
+}
+
 // Values adds a list of values for a row in INSERT.
 func (ib *InsertBuilder) Values(value ...interface{}) *InsertBuilder {
 	placeholders := make([]string, 0, len(value))
@@ -167,6 +177,14 @@ func (ib *InsertBuilder) BuildWithFlavor(flavor Flavor, initialArg ...interface{
 		ib.injection.WriteTo(buf, insertMarkerAfterCols)
 	}
 
+	if ib.sbHolder != "" {
+		buf.WriteString(" ")
+		buf.WriteString(ib.sbHolder)
+
+		ib.injection.WriteTo(buf, insertMarkerAfterSelect)
+		return ib.args.CompileWithFlavor(buf.String(), flavor, initialArg...)
+	}
+
 	if len(ib.values) > 0 {
 		buf.WriteLeadingString("VALUES ")
 		values := make([]string, 0, len(ib.values))

insert_test.go

@@ -179,3 +179,35 @@ func ExampleInsertBuilder_SQL() {
 	// /* before */ INSERT INTO demo.user PARTITION (p0) (id, name, status, created_at) /* after cols */ VALUES (?, ?, ?, ?) ON DUPLICATE KEY UPDATE status = ?
 	// [3 Shawn Du 1 1234567890 1]
 }
+
+func ExampleInsertBuilder_subSelect() {
+	ib := NewInsertBuilder()
+	ib.InsertInto("demo.user")
+	ib.Cols("id", "name")
+	sb := ib.Select("id", "name").From("demo.test")
+	sb.Where(sb.EQ("id", 1))
+
+	sql, args := ib.Build()
+	fmt.Println(sql)
+	fmt.Println(args)
+
+	// Output:
+	// INSERT INTO demo.user (id, name) SELECT id, name FROM demo.test WHERE id = ?
+	// [1]
+}
+
+func ExampleInsertBuilder_subSelect_oracle() {
+	ib := Oracle.NewInsertBuilder()
+	ib.InsertInto("demo.user")
+	ib.Cols("id", "name")
+	sb := ib.Select("id", "name").From("demo.test")
+	sb.Where(sb.EQ("id", 1))
+
+	sql, args := ib.Build()
+	fmt.Println(sql)
+	fmt.Println(args)
+
+	// Output:
+	// INSERT INTO demo.user (id, name) SELECT id, name FROM demo.test WHERE id = :1
+	// [1]
+}