如何使用Sequelize在同一张表上创建外键？

Sequelize很不错，但有时可能会带来挑战。我有一个无法解决的简单示例：表格：ANIMALS

ID     PARENT_ID     LABEL
-------------------------------
1                    ANIMAL
2      1             MAMMAL
3      1             OVOVIPARUS
4      2             PRIMATES
5      2             CARNIVORA

序列化实体：

const Animals = db.define('Animal',
    {
        id: {
            type: Sequelize.INTEGER,
            allowNull: false,
            primaryKey: true,
        },
        parentId: {
            type: Sequelize.INTEGER,
        },
        Label: {
            type: Sequelize.VARCHAR(20),
        },

而且我想这样获取数据：

[
  {id:1, superclass: null, label:'ANIMAL'},
  {id:2, superclass: {id:1, parent: null, label:'ANIMAL'}, label:'MAMMAL'},
  {id:3, superclass: {id:1, parent: null, label:'ANIMAL'}, label:'OVOVIPARUS'},
...
]

并可选地添加子项

[
  {
    id:1, 
    superclass: null, 
    subclasses: [ {id:2, label:'MAMMAL'}, {id:3, label:'OVOVIPARUS'},],
    label:'ANIMAL'},
...
]

我应该如何定义关系？谢谢

您可以定义自我关联。

Animal.hasOne(Animal, {as: 'Parent'});
Animal.belongsTo(Animal, {as: 'Parent'});