Question

我有以下架构：

var userSchema = new mongoose.Schema({
    username: {type: String, required: true},
    favouriteItems: [{type: mongoose.Schema.Types.ObjectId, ref: 'Item'}],
    userItems: [{type: mongoose.Schema.Types.ObjectId, ref: 'Item'}]
});

var itemSchema = new mongoose.Schema({
    name: {type: String, required: true},
    price: {type: Number, required: true}
});

mongoose.model('User', userSchema , 'Users');
mongoose.model('Item', itemSchema , 'Items');

删除项目时，我要从其数组包含该项目的所有用户中从favouriteItems和userItems删除其ObjectId。

示例：

初始：

Users:
[
    {
        _id: "a",
        username: "username1",
        favouriteItems: ["id1"],
        userItems: ["id2", "id3"]
    },
    {
        _id: "b",
        username: "username2",
        favouriteItems: ["id2"],
        userItems: ["id1", "id4"]
    },
    ...
]

Items:
[
    {
        _id: "id1",
        name: "item1",
        price: 19
    },
    {
        _id: "id2",
        name: "item2",
        price: 7
    },
    ...
]

当我删除ID为id1的项目时，我想要以下结果（必须从所有用户的数组id1和favouriteItems中删除userItems）：

Users:
[
    {
        _id: "a",
        username: "username1",
        favouriteItems: [],
        userItems: ["id2", "id3"]
    },
    {
        _id: "b",
        username: "username2",
        favouriteItems: ["id2"],
        userItems: ["id4"]
    },
    ...
]

Items:
[
    {
        _id: "id2",
        name: "item2",
        price: 7
    },
    ...
]

如何使用猫鼬和 node.js 实现这一目标？

Answer 1

您应该看一下post mongoose middleware hooks，尤其是remove上的钩子：

itemSchema.post('remove', async function(doc) {
  // doc is removed ... execute query to remove from favorites using the `doc._id`
});

删除数组中所有出现的ObjectId

1 个答案: