dialect/sql/sqlgraph: allow update single node without select

dialect/sql/sqlgraph/graph.go

@@ -671,6 +671,11 @@ func (u *updater) node(ctx context.Context, tx dialect.ExecQuerier) error {
 	if err := u.setExternalEdges(ctx, []driver.Value{id}, addEdges, clearEdges); err != nil {
 		return err
 	}
+	// Ignore querying the database when there's nothing
+	// to scan into it.
+	if u.ScanValues == nil {
+		return nil
+	}
 	selector := u.builder.Select(u.Node.Columns...).
 		From(u.builder.Table(u.Node.Table).Schema(u.Node.Schema)).
 		Where(sql.EQ(u.Node.ID.Column, u.Node.ID.Value))

dialect/sql/sqlgraph/graph_test.go

@@ -1545,6 +1545,30 @@ func TestUpdateNode(t *testing.T) {
 	}
 }
 
+func TestExecUpdateNode(t *testing.T) {
+	db, mock, err := sqlmock.New()
+	require.NoError(t, err)
+	mock.ExpectBegin()
+	mock.ExpectExec(escape("UPDATE `users` SET `age` = ?, `name` = ? WHERE `id` = ?")).
+		WithArgs(30, "Ariel", 1).
+		WillReturnResult(sqlmock.NewResult(1, 1))
+	mock.ExpectCommit()
+	err = UpdateNode(context.Background(), sql.OpenDB("", db), &UpdateSpec{
+		Node: &NodeSpec{
+			Table:   "users",
+			Columns: []string{"id", "name", "age"},
+			ID:      &FieldSpec{Column: "id", Type: field.TypeInt, Value: 1},
+		},
+		Fields: FieldMut{
+			Set: []*FieldSpec{
+				{Column: "age", Type: field.TypeInt, Value: 30},
+				{Column: "name", Type: field.TypeString, Value: "Ariel"},
+			},
+		},
+	})
+	require.NoError(t, err)
+}
+
 func TestUpdateNodes(t *testing.T) {
 	tests := []struct {
 		name         string