Find document with array that contains a specific value

Question

If I have this schema...

person = {
    name : String,
    favoriteFoods : Array
}

... where the favoriteFoods array is populated with strings. How can I find all persons that have "sushi" as their favorite food using mongoose?

I was hoping for something along the lines of:

PersonModel.find({ favoriteFoods : { $contains : "sushi" }, function(...) {...});

(I know that there is no $contains in mongodb, just explaining what I was expecting to find before knowing the solution)

Answer 1

As favouriteFoods is a simple array of strings, you can just query that field directly:

PersonModel.find({ favouriteFoods: "sushi" }, ...); // favouriteFoods contains "sushi"

But I'd also recommend making the string array explicit in your schema:

person = {
    name : String,
    favouriteFoods : [String]
}

The relevant documentation can be found here: https://docs.mongodb.com/manual/tutorial/query-arrays/

Answer 2

There is no $contains operator in mongodb.

You can use the answer from JohnnyHK as that works. The closest analogy to contains that mongo has is $in, using this your query would look like:

PersonModel.find({ favouriteFoods: { "$in" : ["sushi"]} }, ...);

Answer 3

I feel like $all would be more appropriate in this situation. If you are looking for person that is into sushi you do :

PersonModel.find({ favoriteFood : { $all : ["sushi"] }, ...})

As you might want to filter more your search, like so :

PersonModel.find({ favoriteFood : { $all : ["sushi", "bananas"] }, ...})

$in is like OR and $all like AND. Check this : https://docs.mongodb.com/manual/reference/operator/query/all/