return "CONSTRAINT ? CHECK (?)", []interface{}{clause.Column{Name: chk.Name}, clause.Expr{SQL: chk.Constraint}}
}

// ParseCheckConstraints parse schema check constraints
func (schema *Schema) ParseCheckConstraints() map[string]CheckConstraint {
	checks := map[string]CheckConstraint{}
	for _, field := range schema.FieldsByDBName {
		if chk := field.TagSettings["CHECK"]; chk != "" {
			names := strings.Split(chk, ",")

	}
}

func TestPostgres(t *testing.T) {
	if DB.Dialector.Name() != "postgres" {
		t.Skip()
	}

	type Harumph struct {
		gorm.Model
		Name      string         `gorm:"check:name_checker,name <> ''"`
		Test      uuid.UUID      `gorm:"type:uuid;not null;default:gen_random_uuid()"`
		CreatedAt time.Time      `gorm:"type:TIMESTAMP WITHOUT TIME ZONE"`

	var (
		alterColumn bool
		isSameType  = fullDataType == realDataType
	)

	if !field.PrimaryKey {
		// check type
		if !strings.HasPrefix(fullDataType, realDataType) {
			// check type aliases
			aliases := m.DB.Migrator().GetTypeAliases(realDataType)
			for _, alias := range aliases {
				if strings.HasPrefix(fullDataType, alias) {
					isSameType = true

	}

	if len(omits) > 0 {
		tx = tx.Omit(omits...)
	}

	return db.AddError(tx.Create(values).Error)
}

// check association values has been saved
// if values kind is Struct, check it has been saved
// if values kind is Slice/Array, check all items have been saved
var visitMapStoreKey = "gorm:saved_association_map"

func checkAssociationsSaved(db *gorm.DB, values reflect.Value) bool {

// RelationshipFKName generate fk name for relation
func (ns NamingStrategy) RelationshipFKName(rel Relationship) string {
	return ns.formatName("fk", rel.Schema.Table, ns.toDBName(rel.Name))
}

// CheckerName generate checker name
func (ns NamingStrategy) CheckerName(table, column string) string {
	return ns.formatName("chk", table, column)
}

// IndexName generate index name
func (ns NamingStrategy) IndexName(table, column string) string {

		}
	}

	return ""
}

func IsValidDBNameChar(c rune) bool {
	return !unicode.IsLetter(c) && !unicode.IsNumber(c) && c != '.' && c != '*' && c != '_' && c != '$' && c != '@'
}

// CheckTruth check string true or not
func CheckTruth(vals ...string) bool {
	for _, val := range vals {
		if val != "" && !strings.EqualFold(val, "false") {
			return true
		}
	}
	return false
}

	if idxName != "idx_public_table_name" {
		t.Errorf("invalid index name generated, got %v", idxName)
	}

	chkName := ns.CheckerName("public.table", "name")
	if chkName != "chk_public_table_name" {
		t.Errorf("invalid checker name generated, got %v", chkName)
	}

	joinTable := ns.JoinTableName("user_languages")
	if joinTable != "public.user_languages" {
		t.Errorf("invalid join table generated, got %v", joinTable)
	}

	ErrForeignKeyViolated = errors.New("violates foreign key constraint")
	// ErrCheckConstraintViolated occurs when there is a check constraint violation
	ErrCheckConstraintViolated = errors.New("violates check constraint")

}

// ViewOption view option
type ViewOption struct {
	Replace     bool   // If true, exec `CREATE`. If false, exec `CREATE OR REPLACE`
	CheckOption string // optional. e.g. `WITH [ CASCADED | LOCAL ] CHECK OPTION`
	Query       *DB    // required subquery.
}

// ColumnType column type interface
type ColumnType interface {
	Name() string
	DatabaseTypeName() string                 // varchar

			t.Fatalf("Should have index on %s", "CompanyI.")
		}

		if !m.HasIndex(&DynamicUser{}, "DeletedAt") {
			t.Fatalf("Should have index on deleted_at.")
		}
	}
}

// check column order after migration, flaky test
// https://github.com/go-gorm/gorm/issues/4351
func TestMigrateColumnOrder(t *testing.T) {
	type UserMigrateColumn struct {
		ID uint
	}