mongoose独立的，用文档填充的

I have the following model:

我有以下模型:

var followerSchema = new Schema({
    id_follower: {type: Schema.Types.ObjectId, ref: 'Users'},
    id_post: {type: Schema.Types.ObjectId, ref: 'Posts'}
});

I want to be able to find all posts for a list of followers. When I use find, it returns me of course multiple times the same post as multiple users can follow the same post.

我希望能够找到所有的跟随者的帖子。当我使用find时，它返回的当然是同一个post的倍数，因为多个用户可以使用同一个post。

So I tried to use distinct, but I have the feeling the "populate" does not work afterwards.

所以我尝试使用不同的，但是我有一种感觉，“填充”在之后不会起作用。

Here is my code:

这是我的代码:

followerModel
    .distinct('id_post',{id_follower:{$in:followerIds}})
    .populate('id_post')
    .sort({'id_post.creationDate':1})
    .exec(function (err, postFollowers) {
        console.log(postFollowers);
    })

It only returns me the array of the posts, and it is not populated.

它只返回post的数组，没有填充。

I am new to mongoDB, but according to the documentation of mongoose, the "distinct" method should return a query, just as the "find" method. And on a query you can execute the "populate" method, so I don't see what I am doing wrong.

我是mongoDB的新手，但是根据mongoose的文档，“不同”方法应该返回一个查询，就像“查找”方法一样。在查询中，可以执行“populate”方法，这样我就不会看到哪里出错了。

I also tried to use the .distinct() method of the query, so then my code was like this:

我还尝试使用查询的.distinct()方法，所以我的代码是这样的:

followerModel
    .find({id_follower:{$in:followerIds}})
    .populate('id_post')
    .distinct('id_post')
    .sort({'id_post.creationDate':1})
    .exec(function (err, postFollowers) {
        console.log(postFollowers);
    })

In that case it works, but as in the documentation of mongoose you need to provide a callback function when you use the distinct method on a query, and so in my logs I get errors all over. A workaround would be to have a dummy callback function, but I want to avoid that...

在这种情况下，它可以工作，但是在mongoose的文档中，当您在查询中使用不同的方法时，您需要提供一个回调函数，因此在我的日志中，到处都是错误。一个解决方案是有一个虚拟回调函数，但我想避免……

Does anybody has an idea why the first attempt is not working? And if the second approach is acceptable by providing a dummy callback?

有人知道为什么第一次尝试行不通吗?如果第二种方法可以通过提供一个虚拟回叫来接受呢?

1 个解决方案

#1

Would this be the right way considering the current lack of support in mongoose?

考虑到目前蒙古缺乏支持，这是正确的做法吗?

followerModel
.find({id_follower:{$in:followerIds}})
.distinct('id_post',function(error,ids) {
   Posts.find({'_id':{$in : ids}},function(err,result) {
     console.log(result);
   });
});