How to correctly fetch data from firebase using where clauses and custom filters from firebase using flutter - flutter

Question

Im trying to fetch data using
Stream<List<User>> getUsers(User user) {
return _firebaseFirestore
.collection('users')
// .where('interestedIn', isEqualTo: _selectInterest(user))
.snapshots()
.map((snap) {
return snap.docs.map((doc) => User.fromSnapshot(doc)).toList();
});
}
The filter used in the where clause is as follows
_selectInterest(User user) {
if (user.interestPreference == null) {
return ['HIRING', 'WORK'];
}
return user.interestPreference;
}
In firebase I store interestPreference as an Array with 'HIRING' as the only element in the current user's data, when I try to fetch users with 'HIRING' in their interestedIn which is a string I dont get any data. But when I hardcode the where clause as
.where('interestedIn', isEqualTo: 'HIRING')
I get the data, Can anyone help me solve my dilemma?

Answer 1

From that last query, it sounds like the interestedIn field in your database is a single string value, like interestedIn: "HIRING".
Your current query returns documents where interestedIn is an array with exactly the two values you specify, so interestedIn: ['HIRING', 'WORK']
If you want to return all documents where interested in is either "HIRING" or "WORK", you can use an IN condition:
.where('interestedIn', whereIn: ['HIRING', 'WORK'])
Or with your helper function:
.where('interestedIn', whereIn: _selectInterest(user))