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 {
	CouponId  int    `gorm:"primarykey;size:255"`
	ProductId string `gorm:"primarykey;size:255"`
	Desc      string
}

type Order struct {

	type UserWithUniqueIndex struct {
		ID    int
		Name  string    `gorm:"size:20;index:idx_name,unique"`
		Date  time.Time `gorm:"index:idx_name,unique"`
		UName string    `gorm:"uniqueIndex;size:255"`
	}

	DB.Migrator().DropTable(&UserWithUniqueIndex{})
	if err := DB.AutoMigrate(&UserWithUniqueIndex{}); err != nil {
		t.Fatalf("failed to migrate, got %v", err)
	}

		{"int32", int32(math.MaxInt32), "2147483647"},
		{"int64", int64(math.MaxInt64), "9223372036854775807"},
		{"uint", uint(math.MaxUint64), "18446744073709551615"},
		{"uint8", uint8(math.MaxUint8), "255"},
		{"uint16", uint16(math.MaxUint16), "65535"},
		{"uint32", uint32(math.MaxUint32), "4294967295"},
		{"uint64", uint64(math.MaxUint64), "18446744073709551615"},
		{"string", "abc", "abc"},
		{"other", true, ""},
	}