| Hi, I am running PostgreSQL 9.0.4 and I am getting an error with a SELECT DISTINCT query that contains a point type in the SELECT clause. To be more specific, a query such as: -- explicit declaration that it's a point type SELECT DISTINCT a.geocode::point FROM a WHERE a.region = 'x'; Will return the error: ERROR: could not identify an equality operator for type point I read the notes about how point types do not have "=" defined for them, but "~=" aka the "same as" operator (http://www.postgresql.org/docs/9.0/static/functions-geometry.html). For points, I would treat ~= as equality. I tried creating my own equality operator based on that: CREATE OR REPLACE FUNCTION point_equality(point, point) RETURNS bool AS 'SELECT $1 ~= $2;' LANGUAGE SQL; CREATE OPERATOR = ( LEFTARG = point, RIGHTARG = point, PROCEDURE = point_equality, COMMUTATOR = = ); And when I ran the query again: ERROR: could not identify an equality operator for type point I looked into the mailing list archives and found a potential answer on this thread: http://archives.postgresql.org/pgsql-general/2009-10/msg01122.php However I wanted to see if it was still necessary that I would need the complete btree operator class to run such a query. Are there plans to have a defined "=" operator on the point type? I can understand how the other geometric types, "=" would represent area, but AFAIK I think "=" could be safely applied on a point type (and i realize I could submit a patch for that :-) maybe depending on the resolution to this / refreshing my C...). Is there possibly a relatively quick solution to this issue? Thanks! Jonathan |
