node.js 的猫鼬外键问题

Posted 2023-03-11

【中文标题】node.js 的猫鼬外键问题

【英文标题】：mongoose foreign key problem with node.js

【发布时间】：2020-06-03 17:41:47

【问题描述】：

我有 3 个收藏：

const LeaveSchema = new mongoose.Schema(
 employee: 
        type: mongoose.Schema.Types.ObjectId,
        ref: 'User'
    
)

const UserSchema = new mongoose.Schema(
 company: 
        type: mongoose.Schema.Types.ObjectId,
        ref: 'Company'
    
)

const CompanySchema = new mongoose.Schema(
 //
)

如何获取同一“公司”中“用户”的“叶子”列表

【问题讨论】：

如果您提供了 json 格式的示例文档和预期的输出，那就太好了。还有你已经尝试了什么？

【参考方案1】：

我找到了解决办法：

leaves = await Leave.aggregate([
        
            "$lookup": 
                "from": "users",
                "let":  "companyId": "$employe" ,
                "pipeline": [
                     "$match":  "$expr":  "$eq": ["$_id", "$$companyId"]   ,
                    
                        "$lookup": 
                            "from": "companies",
                            "let":  "companyId": "$company" ,
                            "pipeline": [
                                 "$match":  "_id": new mongoose.Types.ObjectId(company_id),"$expr":  "$eq": ["$_id", "$$companyId"]   
                            ],
                            "as": "companies"
                        
                    ,
                     "$unwind": "$companies" 
                ],
                "as": "users"
            
        ,
         "$unwind": "$users" 
    ])