if err := DB.Model(user).Update("Age", 10).Error; err != nil {
		t.Errorf("errors happened when update: %v", err)
	} else if user.Age != 10 {
		t.Errorf("Age should equals to 10, but got %v", user.Age)
	}
	checkUpdatedAtChanged("Update", user.UpdatedAt)
	checkOtherData("Update")

	var result User
	if err := DB.Where("id = ?", user.ID).First(&result).Error; err != nil {
		t.Errorf("errors happened when query: %v", err)
	} else {

	if err := DB.Model(&user2).Association("Account").Append(&account); err != nil {
		t.Fatalf("Error happened when append Account, got %v", err)
	}

	AssertAssociationCount(t, user2, "Account", 1, "after prepare data")

	// Clear
	if err := DB.Model(&user2).Association("Account").Clear(); err != nil {
		t.Errorf("Error happened when clear Account, got %v", err)
	}

	AssertAssociationCount(t, user2, "Account", 0, "after clear")

	if err := DB.Transaction(func(tx *gorm.DB) error {
		return nil
	}); err == nil {
		t.Errorf("should returns error when commit with closed conn, got error %v", err)
	}

	if err := DB.Session(&gorm.Session{PrepareStmt: true}).Transaction(func(tx *gorm.DB) error {
		return nil
	}); err == nil {
		t.Errorf("should returns error when commit with closed conn, got error %v", err)
	}
}

}

func doCheckPet(t *testing.T, pet Pet, expect Pet, unscoped bool) {
	if pet.ID != 0 {
		var newPet Pet
		if err := db(unscoped).Where("id = ?", pet.ID).First(&newPet).Error; err != nil {
			t.Fatalf("errors happened when query: %v", err)
		} else {
			AssertObjEqual(t, newPet, pet, "ID", "CreatedAt", "UpdatedAt", "DeletedAt", "UserID", "Name")

	if err != nil {
		t.Errorf("Not error should happen, got %v", err)
	}

	type Result struct {
		Name string
		Age  int
	}

	var results []Result
	for rows.Next() {
		var result Result
		if err := DB.ScanRows(rows, &result); err != nil {
			t.Errorf("should get no error, but got %v", err)
		}
		results = append(results, result)
	}

}

func (db *PreparedStmtDB) Ping() error {
	conn, err := db.GetDBConn()
	if err != nil {
		return err
	}
	return conn.Ping()
}

type PreparedStmtTX struct {
	Tx
	PreparedStmtDB *PreparedStmtDB
}

func (db *PreparedStmtTX) GetDBConn() (*sql.DB, error) {
	return db.PreparedStmtDB.GetDBConn()
}

func (tx *PreparedStmtTX) Commit() error {

	}

	if err := DB.Save(&user).Error; err != nil {
		t.Fatalf("errors happened when update: %v", err)
	}

	var user3 User
	DB.Preload("Languages").Preload("Friends").Find(&user3, "id = ?", user.ID)
	CheckUser(t, user2, user3)

	if err := DB.Session(&gorm.Session{FullSaveAssociations: true}).Save(&user).Error; err != nil {
		t.Fatalf("errors happened when update: %v", err)
	}

	var user4 User

type UserWithCallback struct{}

func (UserWithCallback) BeforeSave(*gorm.DB) error {
	return nil
}

func (UserWithCallback) AfterCreate(*gorm.DB) error {
	return nil
}

func TestCallback(t *testing.T) {
	user, err := schema.Parse(&UserWithCallback{}, &sync.Map{}, schema.NamingStrategy{})
	if err != nil {
		t.Fatalf("failed to parse user with callback, got error %v", err)
	}

	for k, ei := range expected {
		t.Run(k, func(t *testing.T) {
			ai, ok := actual[k]
			if !ok {
				t.Errorf("expected index %q but actual missing", k)
				return
			}
			tests.AssertObjEqual(t, ai, ei, "Name", "Class", "Type", "Where", "Comment", "Option")
			if len(ei.Fields) != len(ai.Fields) {
				t.Errorf("expected index %q field length is %d but actual %d", k, len(ei.Fields), len(ai.Fields))
				return
			}

				}

				if name == "" {
					subName := field.Name
					const key = "COMPOSITE"
					if composite, found := settings[key]; found {
						if len(composite) == 0 || composite == key {
							err = fmt.Errorf(
								"The composite tag of %s.%s cannot be empty",
								field.Schema.Name,
								field.Name)
							return
						}
						subName = composite
					}
					name = field.Schema.namer.IndexName(