Subject Regular Expressions & Domains
Author g868avx

I think I might be advised to take this to a development forum, but
here goes anyway....

I have seen from the "Open Requests" list at Sourceforge that a
reques was made some time ago for the use of regexps in the "Where"
clause of a select statement.

However, I was wondering if regexps are usable now. I found this
document on the IBPhonix site:

It talks about the aim to have UDF library in Interbase 5.0 that
would (or might) include a regexp match function.

My question is a) does such a function exist in any available UDF
library (I cannot find it), b) could such a UDF be used in the
definition of a Domain?

It appears to me that this would be a useful thing. My thinking is
that it would allow for a very precise but flexible mechanism for
defining domains. Furthermore, if the definition could itself be
retrieved from the database it could be used in any programming
languages that supported the same school of regexps, thus providing a
single point of control for valid values as data was entered on the

I held back in the past from making such a suggestion because I
realised that it would probably not be compliant with the SQL-92 etc
standards. However, I seem to remember a recent discussion in the
groups here that it was stated that Firebird can have additional
features which are not in SQL 92 if they are useful to users.

I don't mind being told to take this request to the development forum
(is that on Yahoo?), but I would like to know if there is such a UDF
and if the UDF could be used to define a domain. From my reading of
the documentation a domain definition couldn't use a UDF, so I think
this might well have to be made into a feature request.