entc/gen: add support for MapBulkCreate (#3696)

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

@@ -143,6 +143,10 @@ func ({{ $receiver }} *{{ $builder }}) createSpec() (*{{ $.Name }}, *sqlgraph.Cr
 
 // Save creates the {{ $.Name }} entities in the database.
 func ({{ $receiver }} *{{ $builder }}) Save(ctx context.Context) ([]*{{ $.Name }}, error) {
+	{{- /* Initialization error was set by MapCreateBulk. */}}
+	if {{ $receiver }}.err != nil {
+		return nil, {{ $receiver }}.err
+	}
 	specs := make([]*sqlgraph.CreateSpec, len({{ $receiver }}.builders))
 	nodes := make([]*{{ $.Name }}, len({{ $receiver }}.builders))
 	mutators := make([]Mutator, len({{ $receiver }}.builders))

entc/gen/template/dialect/sql/feature/upsert.tmpl

@@ -385,6 +385,9 @@ func (u *{{ $upsertBulk }}) Update(set func(*{{ $upsertSet }})) *{{ $upsertBulk
 
 // Exec executes the query.
 func (u *{{ $upsertBulk }}) Exec(ctx context.Context) error {
+	if u.create.err != nil {
+		return u.create.err
+	}
 	for i, b := range u.create.builders {
 		if len(b.conflict) != 0 {
 			return fmt.Errorf("{{ $pkg }}: OnConflict was set for builder %d. Set it on the {{ $builder }} instead", i)