Is there a way to compare the values of two fields to see if they are
the same?
Let's say we have an index with these fields:
ID: 2
childID: 7
parentID: 0
--------------------
ID: 3
childID: 6
parentID: 5
--------------------
ID: 4
childID: 2
parentID: 2
--------------------
Based on these three documents, I want the query to return the third
document where childID=parentID.
