Generally speaking using try/catch is preferred to examining @@error.

Using try/catch will successfully trap the runtime errors encountered for items 1, 2 and 3.

begin try

insert TESTTABLE

select 1, 'Text1', 1

end try

begin catch

print 'error occured'

end catch

begin try

insert TESTTABLE

select 2, 'Text2xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx', 2

end try

begin catch

print 'error occured'

end catch

begin try

insert TESTTABLE

select 3, 'Text3', 'Text3'

end try

begin catch

print 'error occured'

end catch

However, the error in #4 is going to throw a compile error. That means it will parse fine but the exception is thrown when the engine compiles your statement. That means it can't be caught because it actually happens prior to executing.