如何引用多个模型 mongoose mongodb

Question

我有 3 个模型的 MonthlyMenu。 FrozenFood 和 DailyDeal。

我正在创建一个订单模型，在项目字段内我想拥有来自上述模型之一的项目 ID。

如何在猫鼬模式中引用多个模型？

item: {
  type: mongoose.Schema.Types.ObjectId,
  required: true,
  ref: 'DailyDeal',
},

Answer 1

您可以为此使用 mongoose 虚拟机。首先，通过执行以下操作为您的 order 模式启用虚拟：

const order_schema = new mongoose.Schema({
...
  item: {
    type: mongoose.Schema.Types.ObjectId,
    required: true
  },
...
},
{
    toJSON: { virtuals: true }
});

然后像这样定义 3 个虚拟模式：

order_schema.virtual('frommonthlymenu', {
    ref: 'monthly_menu', // Your MonthlyMenu model name
    localField: 'item', // Your local field, like a `FOREIGN KEY` in RDS
    foreignField: '_id', // Your foreign field which `localField` links to. Like `REFERENCES` in RDS
    // If `justOne` is true, 'members' will be a single doc as opposed to
    // an array. `justOne` is false by default.
    justOne: true
});

order_schema.virtual('fromfrozenfood', {
    ref: 'frozen_food',
    localField: 'item',
    foreignField: '_id',
    justOne: true
});

//Third one here...

然后您可以在查询 order 集合时填充 frommonthlymenu 或 fromfrozenfood 路径。

Lead.find(search_filter)
      .populate('frommonthlymenu')
      .populate('fromfrozenfood')
      .then(result => {
          //Whichever path is populated, that's how you know the collection "item" came from.
      })

如何引用多个模型 mongoose mongodb

How to ref to multiple models mongoose mongodb

mongoose

mongodb

node.js

mongoose-schema