Question

我想根据请求参数在猫鼬集合上自定义搜索火山口

Course.find(
      {
        instTypeId: 1,
        status: 1,
        "institute.instId": req.body.instId,
        "institute.majorId": req.body.majorId
      },
    )

我试图这样做，但是如果req.intId或req.major id为空，则只会获取具有空Institute.instId的记录

如果req.intId或req.major或两者都不想在查找中包含它们

Answer 1

您可以使用Object.assign将值添加到搜索对象（如果存在）：

let instId;
let majorId = 1;

if (instId){
  search = Object.assign(search, {"institute.instId": instId});
}
if (majorId){
  search = Object.assign(search, {"institute.majorId": majorId});
}

Course.find(search , (err, foundCourses) => {
    // Do stuff
});

Answer 2

假设您收到了经过解析的req.body，那么快速而肮脏的方式可能是：

Course.find({
  instTypeId: 1,
  status: 1,
  // if req.body.instId is 'undefined', then it returns false so the expression returns 'null'
  "institute.instId": req.body.instId || null,
  "institute.majorId": req.body.majorId || null
})

您可以用类似的方式构建查询对象：

var query = {}
if (req.body.instId) {
  // using object destructuring
  query = {..., "institute.instId": req.body.instId }
}

但是，建议根据用例设置一些验证

Answer 3

let search = {
  instTypeId: 1,
  status: 1
};
if (req.body.instId) {
  search["institute.instId"] = req.body.instId;
}
if (req.body.majorId) {
  search["institute.majorId"] = req.body.majorId;
}
Course.find(search)

我这样做是为了自定义搜索列

猫鼬，根据要求查找数据

3 个答案: