Message Title

As far as I understand ansinull: If set to true one has to use is not null. If set to false one can use is not null or != null.

> create table rttest (id int identity primary key, i int null, c char(5) null);
> insert into rttest (i) values (1);
(1 row affected)
> select * from rttest;
id          i           c    
----------- ----------- -----
           1           1 NULL 
> select * from rttest where c=null;
id          i           c    
----------- ----------- -----
           1           1 NULL 
(1 row affected)
> select * from rttest where c is null;
id          i           c    
----------- ----------- -----
           1           1 NULL 
(1 row affected)
> set ansinull on;
> select * from rttest where c=null;
id          i           c    
----------- ----------- -----
(0 rows affected)
> select * from rttest where c is null;
id          i           c    
----------- ----------- -----
           1           1 NULL

So I understand that the SybaseASEDialect converts the HQL to is not null or != null depending on ansinull.

But why does it add ADDITIONAL null checks when the parameter is false? How can I write “select * from table where column = null” with ansinull=false in HQL?