Multiple Queries in MS SQL Update query
===

I have an update query in which the where clause contains multiple queries, thus:

Update Table 'tableA' Set FieldA = 'Y' WHERE ID IN ( Select ID from tabA)
                                             OR
                                             ID IN (Select ID from tabB)

Ok, the query above is just a quick example of the query I have, but my question is that I have another field to set in 'tableA' whose value depends upon which of the two queries executes in the where clause. For example if Select ID from tabA returns, then I want to set a value, say in FieldB = 'First Query'. 

So, is there a way of setting a local variable against each query which I can pass to the set clause, or is there another way?

Thanks
