Subject Re: AW: [firebird-support] Temporary Field - Check Field Exist
Author Ann W. Harrison
At 09:29 AM 11/4/2004, Steffen Heil wrote:

>Hi
>
> > I need to create in a Stored Procedure a temporary field, how can I do
>known if it exist before to create it ?
>
>You cannot - or at least, you should not.
>Creating a field means changing meta-data.

That's right

>Changing meta-data is only allowed in single connections and changes will
>not be available until you reconnect to the database.

That's wrong. One specific operation - creating a foreign key -
is restricted to single user mode. Other operations can be done
with the database active, but not if they would impact compiled
requests.

Metadata changes must be committed before they can be used and
stored procedures can not affect the state of transactions - they
can not start transactions, commit, or rollback.

>Use a permanent table with an SPinvocation number (returned from a
>generator).

That's a good suggestion.

Regards,


Ann