ID       uint
			Level1s  []Level1
			Level3ID uint
		}
		Level2_1 struct {
			ID       uint
			Level1s  []Level1 `json:",omitempty"`
			Level3ID uint
		}
		Level3 struct {
			ID       uint
			Name     string
			Level2   Level2
			Level2_1 Level2_1
		}
	)
	DB.Migrator().DropTable(&Level3{}, &Level2{}, &Level1{}, &Level2_1{}, &Level0{})