如何使用环回包含关系过滤数据？

Question

我有三个数据库 table，例如员工、部门和 leave_details。员工和部门使用外键 department_id 建立关系。员工和 leave_details 使用外键 user_id 建立关系我需要从 leave_details where department_id :x

获取数据

我的代码就是这样

leave_details.json

 "relations": {
"employee": {
  "type": "belongsTo",
  "model": "employee",
  "foreignKey": "user_id"
},

和employee.json

 "properties": {"department_id": {
  "type": "number"
}}
 "relations": {
"department": {
  "type": "belongsTo",
  "model": "department",
  "foreignKey": "department_id"
},}

和leave_details.js

 filter = {

    include: [{ relation: 'employee', scope: { where: { department_id: 5} }  }],

    fields: ['id', 'user_id', 'requested_time', 'leave_type', 'leave_start_time', 'leave_status', 'approved_by', 'approval_time', 'leave_end_time'],
    order: 'requested_time DESC',
  };

你能帮帮我吗

Answer 1

迄今为止，使用环回过滤器是不可能的，您需要使用数据库级查询sql/mongodb聚合等

https://github.com/strongloop/loopback/issues/517

在不破坏环回逻辑的情况下进行复杂查询最方便的是mongodb聚合查询，如果你开发一个mixin，你会得到这样的东西：

let filter = {
    where:{},
    include:[],
    ...
    aggregate: [{
        $match: {
            period: {
                $lt: period || new Date()
            }
        }
    },
    {
        $sort: {
            period: -1
        }
    },
    ...]
};

或者使用例如这个 https://github.com/BoLaMN/loopback-mongo-aggregate-mixin

如何使用环回包含关系过滤数据？

How to filter data using loopback include relation?

loopback

node.js

loopbackjs