猫鼬:按ID排序 [英] mongoose: Sorting by id

问题描述

mongo db会在文档更新时对文档重新排序.我很希望这种情况发生，所以我发现使用_id的order将以一致的顺序返回文档.但是现在我无法排序.以下是我的查找查询，该查询查找由特定用户创建的帖子，并且我尝试按_id进行排序. 代码:

mongo db reorders the documents when ever a document is updated. I dint want this to happen so I found that using order by _id would return the documents in consistent order. But now I am not able to sort. Below is my find query which finds posts created by a particular user and I am trying to sort by _id. Code:

app.get('/posts/:user_id',function(req,res){

posts.find({
    'creator.user_id':req.params.user_id
},[],{ sort: { '_id': -1 } },function(err,userpost){
    if(err)
        res.send(err);
    res.json(userpost);


})

});

推荐答案

第二个参数用于选择字段.您需要在第三个参数中添加选项:

The second parameter is for the fields to select. You need to add options to the third parameter:

posts.find({'creator.user_id': req.params.user_id}, null, {sort: {'_id': -1}}, function(err,userpost) {
    if(err)
        res.send(err);
    res.json(userpost);
});

或者，您可以使用sort()函数:

Alternatively you can use the sort() function:

posts.find({'creator.user_id': req.params.user_id}).sort({'_id': -1}).exec(function(err,userpost) {
    if(err)
        res.send(err);
    res.json(userpost);
});

您可以在文档中找到更多示例.

You can find more examples in the documentation.

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