Firebase queries "where contains a string"

Question

I'm trying to do a "where" query in Flutter-Firebase to filter by name (if the object name is "Una casa roja" and the user writes "casa", the object must be returned). I don't know who can I do the query. I only have this, but is not what I am looking for:

.where('nombre', isGreaterThanOrEqualTo: nombre, isLessThan: nombre + 'z')

Thanks!

Answer 1

Firestore doesn't support text-search by default. However, there are a few workarounds.

When you register a new user to your app you can store their username in firestore as an array that includes the possible ways you would search for a user (look at the attached image).

You can do that by splitting the name string.

setSearchParameters(String name) {
        List<String> searchOptions = [];
        String temp = "";
        for (int i = 0; i < name.length; i++) {
          temp = temp + name[i];
          searchOptions.add(temp);
        }
        return searchOptions;
  }

Then you can query the users collection by searching in that array using arrayContains like this:

await usersCollection
        .where('searchOptions', arrayContains: searchText)
        .get()
        .then((value) =>
            value.docs.map((doc) => User.fromSnapShot(doc)).toList());

This solution works for simple cases but if you need advanced search capabilities then you'll have to use a 3rd party service such as Agolia.