ErrInvalidTransaction = errors.New("invalid transaction")
	// ErrNotImplemented not implemented
	ErrNotImplemented = errors.New("not implemented")
	// ErrMissingWhereClause missing where clause
	ErrMissingWhereClause = errors.New("WHERE conditions required")
	// ErrUnsupportedRelation unsupported relations
	ErrUnsupportedRelation = errors.New("unsupported relations")

		schema.err = fmt.Errorf("invalid polymorphic type %v for %v on field %s, missing field %s",
			relation.FieldSchema, schema, field.Name, polymorphic+"Type")
	}

	if relation.Polymorphic.PolymorphicID == nil {
		schema.err = fmt.Errorf("invalid polymorphic type %v for %v on field %s, missing field %s",
			relation.FieldSchema, schema, field.Name, polymorphic+"ID")
	}

	if schema.err == nil {