type ItemContent struct {
		gorm.Model
		ItemID       uint   `gorm:"not null"`
		Name         string `gorm:"not null;type:varchar(50)"`
		LanguageCode string `gorm:"not null;type:varchar(2)"`
	}
	type Item struct {
		gorm.Model
		Logo     string        `gorm:"not null;type:varchar(50)"`
		Contents []ItemContent `gorm:"foreignKey:ItemID"`
	}

	tx := DB.Session(&gorm.Session{})

	}

	if users[1].Age != 19 {
		t.Errorf("user 2's name should be updated, but got %v", users[1].Age)
	}

	DB.Model(users[1]).UpdateColumn("age", gorm.Expr("age + 100 - 50"))
	var user3 User
	DB.First(&user3, users[1].ID)

	users[1].Age += 50
	CheckUser(t, user3, *users[1])

	// update with struct
	DB.Model(users[1]).UpdateColumns(User{Name: "update_column_02_newnew2", Age: 200})

	// update
	sql = DB.ToSQL(func(tx *gorm.DB) *gorm.DB {
		return tx.Model(&User{}).Where("id = ?", 100).Update("name", "Foo bar")
	})
	assertEqualSQL(t, `UPDATE "users" SET "name"='Foo bar',"updated_at"='2021-10-18 19:50:09.438' WHERE id = 100 AND "users"."deleted_at" IS NULL`, sql)