problems using freetds with php & unixodbc

Hello,


I use freetds with php SQLServer2008 and unixodbc
generally it works great, but I have problems with errors and numeric fields with NULL values.

As example I use "SELECT SUM(FIELD) FROM VIEW".
-with tsql in commandline it works fine.
-with iodbc in commandline it works fine.
-with php I get a "No tuples available at this result index" error.

When I change the query to prevent NULLs with the COALESCE function it works with php too.
Is there a workaround for this behavior and what can I do for make the error messages readable?


thanks a lot

Axel