How can I Query the Array dates with the month value?
String monthString = "12";
Query queryZero = db.collection("Users").document(mCurrentUser).collection("Dates").whereArrayContainsAny("dates", ???);
What do I have to put where the '???' to retrieve dates with the dd/MM/yyyy <- /MM/ value is equal to the monthString?
Firestore at the moment does not support this kind of query. But, a possible workaround is to store additional array of months in your document and perform:
db.collection("Users").document(mCurrentUser).collection("Dates").whereArrayContains("months", "12");
Another solution is similar to @Ruyut's answer. But this would retrieve all the documents in the collection and you would have to perform the filtering in the client-side which could possibly degrade performance if you have thousands of documents.
FirebaseFirestore.getInstance().collection("Users")
.get()
.addOnSuccessListener(
new OnSuccessListener<QuerySnapshot>() {
@Override
public void onSuccess(QuerySnapshot documentSnapshots) {
for (DocumentSnapshot ds : documentSnapshots.getDocuments()) {
// same code as @Ruyut's answer
}
}
}
);
public static void getData(){
DatabaseReference database = FirebaseDatabase.getInstance().getReference("Users").child(mCurrentUser).child("Dates");
database_course.addValueEventListener(new ValueEventListener() {
@Override
public void onDataChange(@NonNull DataSnapshot dataSnapshot) {
for (DataSnapshot ds : dataSnapshot.getChildren()) {
String key = ds.getKey(); //7UE......
HashMap<String, ArrayList<String>> datesHashMap = ds.get(key);
for(int i =0;i<datesHashMap.get("dates").size();i++){
String date = datesHashMap.get("dates").get(i);//08/12/2019
if (date.substring(3,5).equals("12")){
//put your code
}
}
}
}
@Override
public void onCancelled(@NonNull DatabaseError databaseError) {
}
});
}
