Why 0s are considered as NULLs...

declare @var bit
select @var = 0
if ISNULL (@Var,'') = '' print 'yes'
else print 'no'
the result is yes when i pass 0. But when i pass 1 for @var, it prints no.
Can anyone explain Why does SQL Server considers 0 as NULLs?

Hi,
SQL Server does not consider 0 = null, but converting '' to bit returns the same value as a 0 bit value (false). This should be clear if you change the above code to:declare @var bit
select
@var = 0 if
@var = '' print 'yes'else
print 'no'