How to query elements inside an array?

Question

How do i query any objects whos array contains a player with a matching case-insensitive name? db.collection.find(players.name: search)

This is a example object of how the data is stored (I've removed all irrelevant fields to the question).

{ "_id" : ObjectId("5d67f29ae6504b451c3aca3e"), "players" : [
 { "name" : "Jenny"}, { "name" : "Benny"}, { "name" : "Kenny" } ] }

One solution would be to just iterate through all documents in the collection and then in turn iterate through all names in each document but I'm trying to avoid this. Another is perhaps to map names to objectIds?

I've done case insenstive before, I'm having problem with the inside an array bit. — Tiago Redaelli, Aug 29 '19 at 17:58
https://stackoverflow.com/questions/10700921/case-insensitive-search-with-in — Mihai Iorga, Aug 29 '19 at 18:02

score 1 · Answer 1 · answered Aug 29 '19 at 21:45

1

You can use a regex to do this:

db.collection.find("players.name": {'$regex' : '^string$', '$options' : 'i'})

answered Aug 29 '19 at 21:45

Juanín

841
6
16

Tiago Redaelli · Answer 2 · 2019-08-29T19:00:02.447

0

Thanks $elemMatch was indeed the solution.

dbo.collection('replays').find({ players: {
        $elemMatch: {name : {$regex: new RegExp('^'+ search + '$', "i") }} 
    }
}).toArray(function (err, res) {
    console.log(res);
});

edited Aug 29 '19 at 19:00

answered Aug 29 '19 at 18:16

Tiago Redaelli

560
5
17

score 0 · Answer 3 · answered Aug 29 '19 at 18:41

Here's my, apparently more traditional, take on it. I didn't know a construct like your own answer here uses exists in the language, I have to do some reading. Anyway, here we go.

function find_player( data, player_name )
{
    return data.filter( (o) => {
        return o.players.find( (player) => {
            return player.name == player_name;
        });
    });
}

let objects = [
    { "_id" : "foo", "players" : [ { "name" : "Jenny"}, { "name" : "Benny"}, { "name" : "Kenny" } ] },
    { "_id" : "bar", "players" : [ { "name" : "Johnny"}, { "name" : "Bunny"}, { "name" : "Kinny" } ] }
];

let found = find_player(objects, "Kinny");

console.log( found[0]._id ); // bar

How to query elements inside an array?

3 Answers3