如何在一个mongoDB查询中两次使用$match运算符

Question

我有两种型号：

const ClientRequest = new mongoose.Schema({
sourceLanguage: {
type: String,
default: '',
trim: true
},
type: {
type: String,
default: '',
trim: true
},
customer: {
type: Schema.Types.ObjectId, ref: 'Client'
}
}

和

const Client = new mongoose.Schema({
name: {
type: String,
default: '',
trim: true
},
web: {
type: String,
default: '',
trim: true
},
country: {
type: String,
default: '',
trim: true
}
}

并且我需要找到所有被sourceLanguage和name过滤的requests。我正在使用这个查询：

const requests = await ClientRequest.aggregate([
{$match: {
"sourceLanguage.symbol": "EN-GB"}
},
{
$lookup: {
from: "clients",
localField: "customer",
foreignField: "_id",
as: "clients"
}
},
{
$match: {
"clients.name": filters.clientFilter,
}
}
])

但它返回空数组。如果我移除其中一个$match，它就会工作。但是，如何在一个查询中同时使用这两个过滤器呢？

Answer 1

const requests = await ClientRequest.aggregate([
{$match: {
"sourceLanguage": "EN-GB",
"customer": ObjectId("5d933c4b8dd2942a17fca425")
}
},
{
$lookup: {
from: "clients",
localField: "customer",
foreignField: "_id",
as: "clients"
}
},
])

Answer 2

我尝试了不同的方法，但有时，最简单的方法是：

const requests = await ClientRequest.aggregate([
{
$lookup: {
from: "clients",
localField: "customer",
foreignField: "_id",
as: "customer" // I used the same name to replace the Id with the unwinded object
}
},
{
$match: {
"customer.name": filters.clientFilter,
"sourceLanguage.symbol": "EN-GB" // or any other filter
}
},
{$unwind: "$customer"} // here I just unwind from array to an object
])