Name       string
	Constraint string // length(phone) >= 10
	*Field
}

func (chk *CheckConstraint) GetName() string { return chk.Name }

func (chk *CheckConstraint) Build() (sql string, vars []interface{}) {
	return "CONSTRAINT ? CHECK (?)", []interface{}{clause.Column{Name: chk.Name}, clause.Expr{SQL: chk.Constraint}}
}

// ParseCheckConstraints parse schema check constraints

	results := map[string]schema.CheckConstraint{
		"name_checker": {
			Name:       "name_checker",
			Constraint: "name <> 'jinzhu'",
		},
		"chk_user_checks_name2": {
			Name:       "chk_user_checks_name2",
			Constraint: "name <> 'jinzhu'",
		},
		"chk_user_checks_name3": {
			Name:       "chk_user_checks_name3",
			Constraint: "name <> 'jinzhu'",
		},
	}

	checks := user.ParseCheckConstraints()

		currentDatabase := m.DB.Migrator().CurrentDatabase()
		constraint, table := m.GuessConstraintInterfaceAndTable(stmt, name)
		if constraint != nil {
			name = constraint.GetName()
		}

		return m.DB.Raw(
			"SELECT count(*) FROM INFORMATION_SCHEMA.table_constraints WHERE constraint_schema = ? AND table_name = ? AND constraint_name = ?",
			currentDatabase, table, name,
		).Row().Scan(&count)
	})

type Language struct {
	Code string `gorm:"primarykey"`
	Name string
}

type Coupon struct {
	ID               int              `gorm:"primarykey; size:255"`
	AppliesToProduct []*CouponProduct `gorm:"foreignKey:CouponId;constraint:OnDelete:CASCADE"`
	AmountOff        uint32           `gorm:"column:amount_off"`
	PercentOff       float32          `gorm:"column:percent_off"`
}

type CouponProduct struct {

}

// IndexName generate index name
func (ns NamingStrategy) IndexName(table, column string) string {
	return ns.formatName("idx", table, ns.toDBName(column))
}

// UniqueName generate unique constraint name
func (ns NamingStrategy) UniqueName(table, column string) string {
	return ns.formatName("uni", table, ns.toDBName(column))
}

func (ns NamingStrategy) formatName(prefix, table, name string) string {

		gorm.Model
		SomeID  string
		OtherID string
		Data    string
	}

	DB.Migrator().DropTable(&Thing{})
	DB.Migrator().CreateTable(&Thing{})
	if err := DB.Exec("ALTER TABLE things ADD CONSTRAINT some_id_other_id_unique UNIQUE (some_id, other_id)").Error; err != nil {
		t.Error(err)
	}

	thing := Thing{
		SomeID:  "1234",
		OtherID: "1234",
		Data:    "something",
	}

	DB.Create(&thing)

		stmt := gorm.Statement{DB: DB}
		stmt.Parse(&Blog{})
		stmt.Schema.LookUpField("ID").Unique = true
		stmt.Parse(&Tag{})
		stmt.Schema.LookUpField("ID").Unique = true
		// postgers only allow unique constraint matching given keys
	}

	DB.Migrator().DropTable(&Blog{}, &Tag{}, "blog_tags", "locale_blog_tags", "shared_blog_tags")
	if err := DB.AutoMigrate(&Blog{}, &Tag{}); err != nil {

	type City struct {
		gorm.Model
		Name string `gorm:"unique"`
	}

	type Museum struct {
		gorm.Model
		Name   string `gorm:"unique"`
		CityID uint
		City   City `gorm:"Constraint:OnUpdate:CASCADE,OnDelete:CASCADE;FOREIGNKEY:CityID;References:ID"`
	}

	db, err := OpenTestConnection(&gorm.Config{TranslateError: true})
	if err != nil {
		t.Fatalf("failed to connect database, got error %v", err)
	}

	sql = "CONSTRAINT ? FOREIGN KEY ? REFERENCES ??"
	if constraint.OnDelete != "" {
		sql += " ON DELETE " + constraint.OnDelete
	}

	if constraint.OnUpdate != "" {
		sql += " ON UPDATE " + constraint.OnUpdate
	}

	foreignKeys := make([]interface{}, 0, len(constraint.ForeignKeys))
	for _, field := range constraint.ForeignKeys {
		foreignKeys = append(foreignKeys, clause.Column{Name: field.DBName})

	Where        Where
	TargetWhere  Where
	OnConstraint string
	DoNothing    bool
	DoUpdates    Set
	UpdateAll    bool
}

func (OnConflict) Name() string {
	return "ON CONFLICT"
}

// Build build onConflict clause
func (onConflict OnConflict) Build(builder Builder) {
	if onConflict.OnConstraint != "" {
		builder.WriteString("ON CONSTRAINT ")
		builder.WriteString(onConflict.OnConstraint)
		builder.WriteByte(' ')
	} else {