t.Fatalf("joins NamedPet and Account should not empty:%v", user1)
	}

	// Account should empty
	DB.Delete(&user1.Account)

	var user2 User
	DB.Model(&User{}).Joins("NamedPet").Joins("Account").First(&user2, user.ID)
	if user2.NamedPet == nil || user2.Account.ID != 0 {
		t.Fatalf("joins Account should not empty:%v", user2)
	}

	// NamedPet should empty
	DB.Delete(&user1.NamedPet)

	var user3 User

		t.Errorf("failed to marshal users, got error %v", err)
	} else if !regexp.MustCompile(`"Team":\[\],"Languages":\[\],"Friends":\[\]`).MatchString(string(r)) {
		t.Errorf("json marshal is not empty slice, got %v", string(r))
	}

	var results []User
	DB.Preload("Team").Preload("Languages").Preload("Friends").Find(&results, "name = ?", user.Name)

	if r, err := json.Marshal(&results); err != nil {

	}
)

func (myType) QueryClauses(f *schema.Field) []clause.Interface {
	return []clause.Interface{emptyQueryClause{Field: f}}
}

func (sd emptyQueryClause) Name() string {
	return "empty"
}

func (sd emptyQueryClause) Build(clause.Builder) {
}

func (sd emptyQueryClause) MergeClause(*clause.Clause) {
}

func (sd emptyQueryClause) ModifyStatement(stmt *gorm.Statement) {

	if DB.Statement.DryRun || DB.DryRun {
		t.Fatal("Failed expect DB.DryRun and DB.Statement.ToSQL to be false")
	}

	if DB.Statement.SQL.String() != "" {
		t.Fatal("Failed expect DB.Statement.SQL to be empty")
	}

	// first
	sql = DB.ToSQL(func(tx *gorm.DB) *gorm.DB {
		return tx.Model(&User{}).Where(&User{Name: "foo", Age: 20}).Limit(10).Offset(5).Order("name ASC").First(&User{})
	})