Find documents through embedded documents in MongoDB using an array of strings?

Question

I am currently practicing MongoDB by building a site powered by it. The db has 5 collections and uses cross-references, either through objectid references or through a hybrid objectid-embedded document system. Mostly things have went very smoothly.

Now, I am trying to build an advanced search function. One field lets you insert multiple strings, separated by commas. In the backend, these will be separated into an array. The objects that are being searched all have an array field which normally contains one or more embedded documents. All of these embedded documents have an objectid reference and a "title" property. This query array I mentioned lets users search for multiple of this title entries, and I want to return all objects that contains the embedded documents with "title" properties all matching the array, so if you search for "X,Y" and there are a document with two embedded documents with the title properties "X" respective "Y" they will be returned, whereas if only of those embedded documents is present, that document will be ignored. The document structure looks like this:

{
    "_id":"5dfcd95fe9d81c32437ba3fb",
     "usedBy":[
     {
       "_id":"5ddaf35f51528c0881e84507",
       "title":"X"
     },
     {
       "_id":"5e00b2c04facc56b40930eac",
       "title":"Y"
     }
    ],
    //more properties follow...
}

So far however, without success. I have tried a few methods, like $in and $elemMatch, but they don't seem to do what I want to have them do. Which method would you suggest? Right now, I tried to converted the array of strings to an array of objects, which in turn are passed to a filter object for the "find"-method:

if(usedBy){
        usedBy = usedBy.split("%5C%2C%2");
        for(var i=0; i<usedBy.length; i++){
            usedBy[i] = {title: usedBy[i]};
        }
        filter.usedBy = usedBy;
    }

Thanks.

Valijon · Accepted Answer · 2020-01-04 18:52:05Z

1

You need to filter by subfield usedBy.title

var titles = usedBy.split(",");
db.collection.find({"usedBy.title":{$in: titles}});

answered Jan 4, 2020 at 18:52

Valijon

13.2k4 gold badges40 silver badges74 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

Saddex Over a year ago

That did put me a great step ahead. Problem is that the filter now gets all documents if that have at least one matched embedded document, when in reality I want all strings to be matched by embedded documents in one document in order for it to be retrieved. Thanks so far though.

Collectives™ on Stack Overflow

Find documents through embedded documents in MongoDB using an array of strings?

1 Answer 1

1 Comment

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

1 Comment

Your Answer

Sign up or log in

Post as a guest

Related