小编Ste*_*ano的帖子

我有4个收藏:人,公司,城市和国家.

人物收藏:

[
  {_id: 1, name: "Mario", surname: "Rossi", company: 2, city: 3, nation: 4},
  {_id: 2, name: "Steve", surname: "Red", company: 2},
  {_id: 3, name: "Alan", surname: "Joe", city: 3},
  {_id: 4, name: "Mark", surname: "Bill", nation: 2},
  {_id: 5, name: "John", surname: "Cena", company: 1, city: 3},
  {_id: 6, name: "Frank", surname: "Avrett", company: 2, nation: 5},
  {_id: 7, name: "Anne", surname: "Swander", nation: 3, city: 8}
]

公司,城市和国家馆藏只有_id和名称栏.
我想要一份包含公司,城市和国家名称的所有人的列表.
如果记录没有得到id公司或城市或国家我想要一个空场.

var aggregate = this.aggregate([
{
    $lookup: { …

我想在 MongoDB 的 mongoose 函数中转换这个 SQL 查询（我的目标是将描述转换为 desc ）。

select description as desc from book

我该如何修复这个功能？

book.find({})
    .lean()
    .exec(function(err, recs) {
       if (err) {
           console.warn(err)
       } else {
           console.log(recs);
     });