> What is in the column? And what do you want to have as
> the result?

I'm dealing with a search feature for a data-entry where all the fields are
just textual fields.
The only thing I know about them is their length.

When the user knows that he's been treating one field as a numeric field, he
might want to test it with a function like that.
If a field represents a year, they can enter things like
"before 1976",
"after 313",
"circa 1999"
"2005",
"1976",
"850".

Saying something like
WHERE THIS_DATE_FIELD > 1950
I'd like the server, if possible, to return all the fields that match the
criterium, where applicable.
I can of course do it with a UDF, but I just wondered whether it'd be
possible with the SQL extensions of Firebird.

> Gimme all rows where AFIELD is small than 20, except
> when it's a value that cannot be converted, then do, eh,
> well, whatever.

I did not invent either CASE or COALESCE, did I?

> Could be me, but why? Isn't this a rather silly question
> to ask from a server?

The fact that the language does not help a user to implement such thing,
doesn't mean the language is poor.
However, neither does it necessarily mean that's a silly request to ask...
;)

Thanks anyway,
Rony