Catching internal error ID's to throw custom errors. Is it possib le in PostGreSQL?

I have a lot of plpgsql functions and I would like to catch the original
postgresql error and, based on that value, to throw with a raise or
something my custom error. In SQL Server, for example, I have the
sysmessages table in which I have all the possible values if the original
errors. I catch that value (named @@error) and I call a function who have a
parameter this value and who will return my custom value. This kind of error
treatment permit me to have the same error ID's in Oracle, SQL Server and
DB2, using a raise with the same error value. Is it possible to do the same
in PostGreSQL using plpgsql language.
Thanks in advanced.

Stefan Ardeleanu
Database Expert / Business Analyst
SIVECO Romania SA

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