Limit is ignored when remove (mongoose)

Question

I need to remove the earliest several documents in a collection, so I wrote something like this:

Model.remove({
    u: "abc"
}).sort({
    _id: 1
}).limit(10).exec(function (err, count) {
    // count gives the total documents number...
});

And this:

Model.find(...).sort(...).limit(...).remove(...);

Hoping someone would help. Thanks.

Answer 1

MongoDB's remove operation doesn't support a limit option, but you can find the _ids of the docs you want to remove, and then use $in to remove them:

Model.find({u: "abc"}).select('_id').sort({_id: 1}).limit(10)
    .exec((err, docs)=> {
        const ids = docs.map((doc)=> doc._id);
        Model.deleteMany({_id: {$in: ids}}, (err)=> {...}); 
    }
);

Answer 2

db.collection.remove() doesn't return a cursor. So, you cannot append cursor methods like sort() or limit(), like you can to a db.collection.find() operation.

You might want to look at db.collection.findAndModify(), to which you can supply a remove parameter to delete a document.