Make the GROUP_CONCAT aggregate function not repeat values (closes #3223975)
Work on sets instead of arrays, so if the same value appears twice it's
not repeated in the concatenated output.
This patch handles the postgresql and sqlite backends, mysql is left
alone at this point (seems doable, but I don't have time or motivation
to fix and test it).
/* -*- sql -*-
postgres specific registered procedures,
require the plpgsql language installed
*/
DROP FUNCTION IF EXISTS comma_join (anyarray) CASCADE;
CREATE FUNCTION comma_join (anyarray) RETURNS text AS $$
SELECT array_to_string($1, ', ')
$$ LANGUAGE SQL;;
CREATE FUNCTION cw_array_append_unique (anyarray, anyelement) RETURNS anyarray AS $$
SELECT array_append($1, (SELECT $2 WHERE $2 <> ALL($1)))
$$ LANGUAGE SQL
DROP AGGREGATE IF EXISTS group_concat (anyelement) CASCADE;
CREATE AGGREGATE group_concat (
basetype = anyelement,
sfunc = cw_array_append_unique,
stype = anyarray,
finalfunc = comma_join,
initcond = '{}'
);;
DROP FUNCTION IF EXISTS limit_size (fulltext text, format text, maxsize integer);
CREATE FUNCTION limit_size (fulltext text, format text, maxsize integer) RETURNS text AS $$
DECLARE
plaintext text;
BEGIN
IF char_length(fulltext) < maxsize THEN
RETURN fulltext;
END IF;
IF format = 'text/html' OR format = 'text/xhtml' OR format = 'text/xml' THEN
plaintext := regexp_replace(fulltext, '<[\\w/][^>]+>', '', 'g');
ELSE
plaintext := fulltext;
END IF;
IF char_length(plaintext) < maxsize THEN
RETURN plaintext;
ELSE
RETURN substring(plaintext from 1 for maxsize) || '...';
END IF;
END
$$ LANGUAGE plpgsql;;
DROP FUNCTION IF EXISTS text_limit_size (fulltext text, maxsize integer);
CREATE FUNCTION text_limit_size (fulltext text, maxsize integer) RETURNS text AS $$
BEGIN
RETURN limit_size(fulltext, 'text/plain', maxsize);
END
$$ LANGUAGE plpgsql;;