I have 2 tables: CREATE TABLE movies ( movies UNIQUE, name, icon_modified );
CREATE TABLE genres ( genres, movies, ); I want to construct genres icons and each icon must display 4 movies. I need to get: genres from genres and movies,icon_modified from movies. This is the query I have: SELECT genres name,count(genres.movies) count,substr(group_concat(grouped.movies,' '),1,40) src,substr(group_concat(grouped.icon_modified,' '),1,80) icon_modified FROM genres LEFT JOIN (SELECT movies,icon_modified FROM movies WHERE icon_modified != '') grouped on grouped.movies = genres.movies GROUP BY genres ORDER BY name" The query works correctly but it is very very slow, it takes 2.474s on my machine, if I run the same query but using JOIN instead of LEFT JOIN it only takes 0.039s Is there any way of optimizing these query? Thanks in advance. -- View this message in context: http://sqlite.1065341.n5.nabble.com/Please-help-me-optimize-this-LEFT-JOIN-query-tp71000.html Sent from the SQLite mailing list archive at Nabble.com. _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
