Re: Primary Key, Unique Key

Now that I understand the differences better, I'm thinking of whether to change my table schemas to use unique keys rather than primary keys. I came across the problem of inserting an empty key string into the table using ODBC calls and the driver comes back to say that I'm inserting a NULL string into a key field. However, if I insert directly into the table specifying insert into table (field1, ....) values (..., '', .....),it's ok. Not if I use ODBC calls to bind the empty string as a parameter for inserting. (specfying that the parameter has 0 length). The problem is I'm not sure if it's a bug in the ODBC library or the way the ODBC driver interprets the parameters is so and there's no way I can specify an empty string as a parameter. (The confusing part is that in the manual, they say it's possible to specify an empty string as a parameter by specifying 0 length for the parameter). I checked with INFORMIX support and it seems they don't have a clue either. Regards, Wan-Ling