I have used it in all forms

Set ansi null on

update employees

set name = ''

and

set @name = 'max'

It should work

IN SQL

IF EXISTS(select 1 from table1

having count(*) = (

select count(*) from table2 ))

--whatever

else

--error

end

select 1 from table1

having count(*) = (

select count(*) from table2 )

Use an activex task after query read result from global variable then decide what to do