if len(v) > 0 {
				writer.WriteByte('(')
				stmt.AddVar(writer, v...)
				writer.WriteByte(')')
			} else {
				writer.WriteString("(NULL)")
			}
		case *DB:
			subdb := v.Session(&Session{Logger: logger.Discard, DryRun: true}).getInstance()
			if v.Statement.SQL.Len() > 0 {
				var (
					vars = subdb.Statement.Vars
					sql  = v.Statement.SQL.String()
				)