Using a `SELECT`, I want to find the row `ID` of 3 columns (each value is unique/dissimilar and is populated by separate tables.) Only the `ID` is auto incremented. 

I have a middle table I reference that has 3 values: ID, A, B.

* A is based on data from another table.
* B is based on data from another table.

How can I select the row ID when I only know the value of A and B, and A and B are not the same value?