Good point on the execution plans EdwardG
. This example may be trivial enough that SELECT * is not better than SELECT 1. I should have stated more clearly that it is good practice to use SELECT * in an EXISTS because it can
give performance improvements. Your mileage may vary.
There is no inherent problem with using the WHILE clause just as I posted it. I certainly didn't sanction the code you posted but it is a good example and well worth noting. You never want to get stuck in an infinite loop. Error checking should also always be done.
DROP TABLE Experimental_parameters
IF @@ERROR <> 0 BEGIN
--DO SOMETHING HERE (i.e. RAISERROR & RETURN)
I just read the OP. I was replying to Re^2: T-SQL problem - Perl solution?
which didn't indicate a temp table or code inside the WHILE. My sanctioned code could yield the behavior EdwardG
posted based on the OP. The OP had
if (SELECT COUNT(*) FROM #Experimental_parameters) <> 0 begin DROP TAB
+LE Experimental_parameters end
Error hanling code needs to be used inside the WHILE.
Good call EdwardG