快递与猫鼬。并在子文档中获取foreignkey子文档
我有使用外键与国家有关的州。虽然取得国家，我无法获得相关国家，但得到一个奇怪的结果。以下是我的模型
国家模型var mongoose = require（'mongoose'）; var Schema = mongoose.Schema
var CountrySchema =Schema(
{
name:{type:String,required:true},
code :{type:String},
status: { type: Boolean, default:true }
}
)
module.exports = mongoose.model('Country', CountrySchema
)
国家模型
var mongoose = require('mongoose');
var Schema=mongoose.Schema
var Country =require('../../models/location/country');
var StateSchema=Schema(
{
name:{type:String,required:true},
code :{type:String},
status: { type: Boolean, default:true },
country: { type: Schema.ObjectId, ref: 'Country', required: true },
country:[Country.schema]
}
)
module.exports = mongoose.model('State', StateSchema)
我的回答如下
{
"data": {
"5a36f32fc6ac751b711e9b19": {
"name": "Kerala",
"code": "KL",
"_id": "5a36f32fc6ac751b711e9b19",
"__v": 0,
"country": [
{
"_bsontype": "ObjectID",
"id": {
"type": "Buffer",
"data": [
90,
47,
16,
175,
152,
157,
109,
20,
5,
111,
70,
142
]
},
"status": true
}
],
"status": true
}
}
}
为什么我为国家获取此类型数据而不是获取正确的数据
回答如下：您向我们展示了可能存在其他问题的api响应。我纯粹在猫鼬层回答你的问题。你需要编辑你的StateSchema所以country没有定义两次。然后使用$looup
const Schema = require('mongoose').Schema;
const mongoose = require('mongoose');
const CountrySchema = Schema({
name: { type: String, required: true },
code: { type: String },
status: { type: Boolean, default: true }
});
const Country = mongoose.model('Country', CountrySchema, 'countries');
const StateSchema = Schema({
name: { type: String, required: true },
code: { type: String },
status: { type: Boolean, default: true },
country: { type: Schema.ObjectId, ref: 'Country', required: true }
});
const State = mongoose.model('State', StateSchema, 'states');
mongoose.connect('mongodb://localhost:27017/test');
mongoose.connection.once('open', async () => {
console.log("Connected to db.");
const australia = await Country.insertMany({
name: 'Australia',
code: 'AU',
status: 'active'
})
await State.insertMany({
name: 'New South Wales',
code: 'NSW',
status: 'active',
country: australia[0]._id
})
const join = await State.aggregate([
{
$lookup: {
from: 'countries',
localField: 'country',
foreignField: '_id',
as: 'country_docs'
}
}
]);
console.log(JSON.stringify(join));
});
$lookup is only available in mongo > 3.2
快递与猫鼬。并在子文档中获取foreignkey子文档
我有使用外键与国家有关的州。虽然取得国家，我无法获得相关国家，但得到一个奇怪的结果。以下是我的模型
国家模型var mongoose = require（'mongoose'）; var Schema = mongoose.Schema
var CountrySchema =Schema(
{
name:{type:String,required:true},
code :{type:String},
status: { type: Boolean, default:true }
}
)
module.exports = mongoose.model('Country', CountrySchema
)
国家模型
var mongoose = require('mongoose');
var Schema=mongoose.Schema
var Country =require('../../models/location/country');
var StateSchema=Schema(
{
name:{type:String,required:true},
code :{type:String},
status: { type: Boolean, default:true },
country: { type: Schema.ObjectId, ref: 'Country', required: true },
country:[Country.schema]
}
)
module.exports = mongoose.model('State', StateSchema)
我的回答如下
{
"data": {
"5a36f32fc6ac751b711e9b19": {
"name": "Kerala",
"code": "KL",
"_id": "5a36f32fc6ac751b711e9b19",
"__v": 0,
"country": [
{
"_bsontype": "ObjectID",
"id": {
"type": "Buffer",
"data": [
90,
47,
16,
175,
152,
157,
109,
20,
5,
111,
70,
142
]
},
"status": true
}
],
"status": true
}
}
}
为什么我为国家获取此类型数据而不是获取正确的数据
回答如下：您向我们展示了可能存在其他问题的api响应。我纯粹在猫鼬层回答你的问题。你需要编辑你的StateSchema所以country没有定义两次。然后使用$looup
const Schema = require('mongoose').Schema;
const mongoose = require('mongoose');
const CountrySchema = Schema({
name: { type: String, required: true },
code: { type: String },
status: { type: Boolean, default: true }
});
const Country = mongoose.model('Country', CountrySchema, 'countries');
const StateSchema = Schema({
name: { type: String, required: true },
code: { type: String },
status: { type: Boolean, default: true },
country: { type: Schema.ObjectId, ref: 'Country', required: true }
});
const State = mongoose.model('State', StateSchema, 'states');
mongoose.connect('mongodb://localhost:27017/test');
mongoose.connection.once('open', async () => {
console.log("Connected to db.");
const australia = await Country.insertMany({
name: 'Australia',
code: 'AU',
status: 'active'
})
await State.insertMany({
name: 'New South Wales',
code: 'NSW',
status: 'active',
country: australia[0]._id
})
const join = await State.aggregate([
{
$lookup: {
from: 'countries',
localField: 'country',
foreignField: '_id',
as: 'country_docs'
}
}
]);
console.log(JSON.stringify(join));
});
$lookup is only available in mongo > 3.2