Is there any function, or a method wich is like ISNULL of MS-SQL.
I need that the result of a SELECT does not contain a NULL value.
Something like this:

Select Isnull(cod,' ') As Cod from mytable

Thanks a lot
Tabacaru Teodor
Ragusa,Italy

You can specify this in the where clause:
select blah
from table
where blah is not null;

Informix has an NVL function that is able to do the following:

SELECT name, NVL(address, "address is unknown")
FROM student

In your case it would be:

Select NVL(cod,' ') As Cod
from mytable