Declare
    v_a_variable varchar2(10);
Begin
  v_a_variable := '';

  --This should succeed but doesn't
  If v_a_variable = '' Then
    dbms_output.put_line('Is Empty String');
  else
    dbms_output.put_line('Is Not an Empty String');
  end if;

  --Oracle converts a value being set to '' to null
  --but Oracle didn't convert the if = '' to if is null which I think it should have done
  If v_a_variable is null Then
    dbms_output.put_line('Variable is null');
  else
    dbms_output.put_line('variable is not null');
  end if;
End;

if v_a_varable = '' Then

if _va_variable is null Then

Declare @v_a_variable varchar(10)

set @v_a_variable = '';

if @v_a_variable = ''
    print 'Is Empty String';
else
    print 'Is not empty';

if @v_a_variable is null
    print 'Is null String';
else
   print 'Is not null';