If I have understood correctly, tbl1 should have the primary key, and the 20+ static fields.

The second table should contain the value of the the primary key from tbl1, the OP value, and the "about 10" fields that vary based on OP. You should probably set a primary key on the first two fields (assuming that each row of tbl1 should only have one set of values for each OP value).


The Select statement will then be quite easy, as the join will be on the primary key of tbl1, and the OP value (which you could put in the Where clause).