From: Chris W
Date: November 29 2012 5:44pm
Subject: Update One of Three tables in a single query
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I have three tables, TableA, TableB, and TableC each has a unique ID 
field, idA, idB, idC respectively each table also has a field called 
'Status'.  The id field is always greater than zero.  Now suppose I have 
three variables A, B, and C.   Two of them are zero and the other is a 
valid ID for the corresponding table.  Only I don't know which one.  Is 
there a way to write a single update statement that will update only the 
one table that has the matching ID?  I have tired a few different ideas 
but none seem worth mentioning here since they all either update too 
many records or don't update any records.

Thanks for the help.

Chris W