unique, ok := columnType.Unique()
	if !ok || field.PrimaryKey {
		return nil // skip primary key
	}
	// By default, ColumnType's Unique is not affected by UniqueIndex, so we don't care about UniqueIndex.
	return m.RunWithValue(value, func(stmt *gorm.Statement) error {
		// We're currently only receiving boolean values on `Unique` tag,
		// so the UniqueConstraint name is fixed

	DB.Migrator().DropTable(&Product{})
	DB.AutoMigrate(&Product{})

	p := Product{Code: "unique_code", Price: 100}
	DB.Save(&p)

	if !reflect.DeepEqual(p.GetCallTimes(), []int64{1, 1, 0, 1, 1, 0, 0, 0, 0}) {
		t.Fatalf("Callbacks should be invoked successfully, %v", p.GetCallTimes())
	}

	DB.Where("Code = ?", "unique_code").First(&p)
	if !reflect.DeepEqual(p.GetCallTimes(), []int64{1, 1, 0, 1, 0, 0, 0, 0, 1}) {

		if err != nil {
			t.Fatalf("failed to parse user unique, got error %v", err)
		}

		constraints := user.ParseUniqueConstraints()
		if len(constraints) != 1 {
			t.Fatalf("failed to find unique constraint, got %v", constraints)
		}

		for key := range constraints {
			if len(key) != 63 {
				t.Errorf("failed to find unique constraint, got %v", constraints)
			}
		}
	})

	}

	if name := DB.Dialector.Name(); name == "postgres" {
		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")

	Serializer             SerializerInterface
	NewValuePool           FieldNewValuePool

	// In some db (e.g. MySQL), Unique and UniqueIndex are indistinguishable.
	// When a column has a (not Mul) UniqueIndex, Migrator always reports its gorm.ColumnType is Unique.
	// It causes field unnecessarily migration.
	// Therefore, we need to record the UniqueIndex on this column (exclude Mul UniqueIndex) for MigrateColumnUnique.

			PkgPath: ownField.StructField.PkgPath,
			Type:    ownField.StructField.Type,
			Tag: removeSettingFromTag(appendSettingFromTag(ownField.StructField.Tag, "primaryKey"),
				"column", "autoincrement", "index", "unique", "uniqueindex"),
		})
	}

	for idx, relField := range refForeignFields {
		joinFieldName := strings.Title(relation.FieldSchema.Name) + relField.Name

		if _, ok := ownFieldsMap[joinFieldName]; ok {

type AssociationEmptyUser struct {
	ID   uint
	Name string
	Pets []AssociationEmptyPet
}

type AssociationEmptyPet struct {
	AssociationEmptyUserID *uint  `gorm:"uniqueIndex:uniq_user_id_name"`
	Name                   string `gorm:"uniqueIndex:uniq_user_id_name;size:256"`
}

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