Maybe you'd have to include expressions like " :arg IS NULL" or ":arg is NOT NULL" when passing in a null value?

regards

Hi Dan;

  Did you try an SQL Trace? 

  SQLCA.DBMS = "TRACE ODB"

Regards ... Chris

Thanks. I do understand what the binding variables does. I guess I was wondering whether anyone had any theory about why my original code could cause a problem with that, and perhaps whether anybody else had seen similar problems with other SQL servers - which could indicate that the problem might originate in PB, rather than the SQL server I'm using.

When Bind Variables is active, PowerBuilder sends the SQL statement with the :varname occurences in it and the variable values are sent separately. The database server makes the variable substitutions before running the statement.

If Bind Variables is inactive, PowerBuilder makes the substitutions before sending the SQL statement.

Bind Variables allows the database server to cache the statement along with its execution plan. If the same statement is run frequently, it can be faster since it only has to do the variable substitution before running it.

It is possible that Firebird doesn't handle bind variables the way it should.

I would try to track down on the server side what is actually been sent/processed.  I have no idea if firebird has those types of tools?  

I'm a big fan of always using coalesce instead of an (OR col > somevalue):

so i would just write it with that, and if it works, i'd call it a day.....

( coalesce(member_number,-1) = :MemberNumber OR coalesce(email, '>') = :Email )