I need to query a Firebase list based on two keys and values. For example:
books
-gdhagd342363
status:'Active'
authers
-yruywert676:'john markos'
-eiuqwbj8200:'mark solo'
-jdfhs8797429
status:'Active'
authers
-yruywert676:'john markos'
So I want to find how many books are (status=='Active') AND (the key of the authers child == -yruywert676).
How to implement such query ?