Adam Mackler <pgsql-general@mackler.org> wrote:
> CREATE domain my_domain as char(3) check(VALUE similar to '[A-C]{3}');
> CREATE TABLE my_table (val my_domain);
> INSERT INTO my_table VALUES ('ABC');
> sandbox=> SELECT * FROM my_table WHERE val='abc';
> val
> -----
> (0 rows)
>
> Question: What can I do so my custom equality operator is used without
> the cast?
If you are trying to get this particular case to work, you are
going about it the hard way, since case-insensitive comparisons are
supported by the citext extension. This particular case could be
solved by:
CREATE EXTENSION citext;
CREATE domain my_domain as citext check(VALUE ~ '^[A-C]{3}$');
CREATE TABLE my_table (val my_domain);
INSERT INTO my_table VALUES ('ABC');
SELECT * FROM my_table WHERE val = 'abc';
If this is just a simplified example, you might want to look at the
CREATE CAST statement.
http://www.postgresql.org/docs/current/interactive/sql-createcast.html
Or look through the source code for the citext extension to see
what other sorts of issues you might need to cover.
--
Kevin Grittner
EDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company
