> I'd like to add checks to some VARCHAR domains that would make sure all
> characters are digits, or alphanumeric, or just alpha. Can anyone give
> me a pointer (I do have the FB book) to the functions or keywords
> needed? Thanks.

Either write UDF, or, if you do not want to bother with installing UDF,
write selectable stored procedure and call it using CHECK(EXISTS(...))
in the domain definition.

Ivan