firebase - Firestore how to query field containing any of the values in the array

Question

Say my Firestore DB contains a collection of documents, each with a field that contains a large array of numbers. For Example:

{
arr: [11,13,24,16,37,50]
},
{
arr: [12,34,55,56]
},
{
arr: [12,16,27,59]
}

How can I make a query that returns all the documents where the 'arr' field contains any of the values in a certain array?

For example, if I query with [16,13] I get the first and third documents only (first one contains both 16 and 13, third one contains 16).

Please note that both the 'arr' array and the array in my query can contain a large number of values (> 1000), so I can't use 'array-contains-any'.

Is it possible to do that? Can I structure my DB differently in order to achieve that goal?

question from:https://stackoverflow.com/questions/65838086/firestore-how-to-query-field-containing-any-of-the-values-in-the-array

Answer 1

As you know, array-contains-any support up to 10 comparison values. If you have a large array of over 1000 values, then you might be better to restructure your collection to something like this:

Example:

arr:
  arr_name:
    title: "arr_title"
        arr_1: {
            "10": true,
            "11": true,
            "12": true
        }

Example:

db.collection("arr_name")
    .whereField("arr_1.10", isEqualTo: true)
    .whereField("arr_1.12", isEqualTo: true)