Andy Kelly shows how to prevent part of a script from running:
If we were to hit F5 (or however you execute your TSQL statements in SSMS) without highlighting any statement(s) they would all be executed, one batch after the other. Even if one batch were to fail or we had a THROW in that batch it would fail at that point but execution would continue immediately after the next GO until the end. This is where SET NOEXEC ON comes into play. If I add that at the beginning of the script all succeeding code would not be executed. The statements would only be compiled and not actually run. It would look like this:
SET NOEXEC ON;
PRINT ‘Got Here 1’ ;
GO
PRINT ‘Got Here 2’ ;
GO
PRINT ‘Got Here 3’ ;
GO
PRINT ‘Got Here 4’ ;
GO
This is a useful “accidental F5” protection: you can put it at the top of your long script to keep from running the whole thing at once.