Odbc parser error

Hi all,

Seems that ODBC driver have some problems while it translate Access
commands.
I created a form with a subform joined by two columns.

after the Access Addnew event, log file returns the following error:
-----------------------------------------------------------------------
conn=75511800, query='SELECT "risanamento"."oid" FROM "risanamento" WHERE (("distretto" =  '' ) AND ("progressivo" =
NULL) ) ' 
ERROR from backend during send_query: 'ERROR:  parser: parse error at or near "null"'
STATEMENT ERROR: func=SC_execute, desc='', errnum=1, errmsg='Error while executing the query'
------------------------------------------------------------------------
NB: Note that parser translate ("progressivo" =  NULL) instead of
("progressivo" IS NULL).


I suspect that problem is linked with column type, in fact
"progressivo" is an int4. I changed this field to char and now it
works:
----------------------------------------------------------------------------------
conn=92477940, query='SELECT "risanamento"."oid" FROM "risanamento" WHERE (("distretto" =  '' ) AND ("progressivo" =
'') ) ' 
------------------------------------------------------------------------------------

"progressivo" is a counter field and it must be numeric.

Any hints will be appreciate.

Thank you in advance,
 Marco Pollachini                          mailto:sferac@bo.nettuno.it