if err := execTx.Migrator().CreateConstraint(value, constraint.Name); err != nil {
								return err
							}
						}
					}
				}

				for _, chk := range parseCheckConstraints {
					if !queryTx.Migrator().HasConstraint(value, chk.Name) {
						if err := execTx.Migrator().CreateConstraint(value, chk.Name); err != nil {
							return err
						}
					}
				}

	ColumnTypes(dst interface{}) ([]ColumnType, error)

	// Views
	CreateView(name string, option ViewOption) error
	DropView(name string) error

	// Constraints
	CreateConstraint(dst interface{}, name string) error
	DropConstraint(dst interface{}, name string) error
	HasConstraint(dst interface{}, name string) bool

	// Indexes
	CreateIndex(dst interface{}, name string) error

			DB.Migrator().CreateConstraint(&User{}, name)
		}

		if err := DB.Migrator().DropConstraint(&User{}, name); err != nil {
			t.Fatalf("failed to drop constraint %v, got error %v", name, err)
		}

		if DB.Migrator().HasConstraint(&User{}, name) {
			t.Fatalf("constraint %v should been deleted", name)
		}

		if err := DB.Migrator().CreateConstraint(&User{}, name); err != nil {