Lateral - initial commit.

internal/jet/select_table.go

@@ -13,8 +13,8 @@ type selectTableImpl struct {
 }
 
 // NewSelectTable func
-func NewSelectTable(selectStmt SerializerStatement, alias string) SelectTable {
-	selectTable := &selectTableImpl{selectStmt: selectStmt, alias: alias}
+func NewSelectTable(selectStmt SerializerStatement, alias string) selectTableImpl {
+	selectTable := selectTableImpl{selectStmt: selectStmt, alias: alias}
 	return selectTable
 }
 
@@ -38,3 +38,21 @@ func (s selectTableImpl) serialize(statement StatementType, out *SQLBuilder, opt
 	out.WriteString("AS")
 	out.WriteIdentifier(s.alias)
 }
+
+// --------------------------------------
+
+type lateralImpl struct {
+	selectTableImpl
+}
+
+func NewLateral(selectStmt SerializerStatement, alias string) SelectTable {
+	return lateralImpl{selectTableImpl: NewSelectTable(selectStmt, alias)}
+}
+
+func (s lateralImpl) serialize(statement StatementType, out *SQLBuilder, options ...SerializeOption) {
+	out.WriteString("LATERAL")
+	s.selectStmt.serialize(statement, out)
+
+	out.WriteString("AS")
+	out.WriteIdentifier(s.alias)
+}

postgres/lateral.go

@@ -0,0 +1,13 @@
+package postgres
+
+import "github.com/go-jet/jet/v2/internal/jet"
+
+func LATERAL(selectStmt SelectStatement, alias string) SelectTable {
+	subQuery := &selectTableImpl{
+		SelectTable: jet.NewLateral(selectStmt, alias),
+	}
+
+	subQuery.readableTableInterfaceImpl.parent = subQuery
+
+	return subQuery
+}

postgres/lateral_test.go

@@ -0,0 +1,9 @@
+package postgres
+
+import "testing"
+
+func TestLATERAL(t *testing.T) {
+	assertSerialize(t, LATERAL(SELECT(Int(1)), "lat1"), `LATERAL (
+     SELECT $1
+) AS lat1`)
+}

tests/postgres/select_test.go

@@ -1893,3 +1893,34 @@ WHERE ($1 AND (customer.customer_id = $2)) AND (customer.activebool = $3);
 	require.Len(t, dest, 1)
 	testutils.AssertDeepEqual(t, dest[0], customer0)
 }
+
+func TestLateral(t *testing.T) {
+
+	languages := LATERAL(
+		SELECT(
+			Language.AllColumns,
+		).FROM(
+			Language,
+		).WHERE(
+			Language.Name.NOT_IN(String("spanish")).
+				AND(Film.LanguageID.EQ(Language.LanguageID)),
+		),
+		"films")
+
+	stmt := SELECT(
+		Film.AllColumns,
+		languages.AllColumns(),
+	).FROM(
+		Film.CROSS_JOIN(languages),
+	).WHERE(
+		Film.FilmID.EQ(Int(1)),
+	)
+
+	var dest []struct {
+		model.Film
+		model.Language
+	}
+
+	err := stmt.Query(db, &dest)
+	require.NoError(t, err)
+}