Blocking Friends SQL (Super Slow SQL ??)
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15-11-2019 - |
Domanda
Ciao sto avendo problemi con questo sql.Fondamentalmente mostra gli stati che i miei amici hanno pubblicato, e filtra gli amici che ho bloccato.
L'SQL è SLOOOOOWWWWW però .. ci vogliono 2 secondi per elaborarlo.Quello che sembra essere il problema.(Ive ha elencato le tabelle e alcuni esempi di come appare sotto il SQL) grazie in anticipo! SQL ....
SELECT from_user_id,content,wall.date, wall.wall_type, users.id, users.displayname
FROM wall
INNER JOIN friendship ON ( wall.from_user_id =friendship.user_a OR wall.from_user_id = friendship.user_b )
INNER JOIN users ON (wall.from_user_id = users.id)WHERE users.id not in (select blocked_id from blocklist where user_id = 1) and (wall.wall_type = 'home' OR wall.wall_type = 'profile' or wall.wall_type = 'topro') AND (
(friendship.user_a = 1 and friendship.user_b = wall.from_user_id)
or
(friendship.user_a = wall.from_user_id and friendship.user_b = 1) or (wall.user_id_of_wall = 1 or type_id = 1 or from_user_id = 1))GROUP BY wall_id ORDER BY date DESC LIMIT 10
.
(Nome tabella: BlockList)
user_id | blocked_id
1 74
1 70
1 94
1 81
.
(Nome tabella: Accoglienza)
user_a user_b status date
1 93 1 1297323354
1 79 1 1297323409
1 81 1 1297323403
1 82 1 1297323398
1 85 1 1297323389
1 90 1 1297323367
1 89 1 1297323373
.
(Nome tabella: Utenti)
id displayname
1 Kenny Jack
8 Wale Robinson
7 Victor WIlliams
6 Micheal Harris
9 Micheal Boston
10 Yestor Smith
.
Il tavolo da parete
wall_id wall_type user_id_of_wall type_id from_user_id content viewed date
5 profile 8 8 8 Just chilling! 0 1296858001
.
Grazie !!!
Soluzione
NOT IN is used for fixed values, use NOT EXISTS instead :
SELECT from_user_id,content,wall.date, wall.wall_type, users.id, users.displayname
FROM wall
INNER JOIN friendship ON ( wall.from_user_id =friendship.user_a OR wall.from_user_id = friendship.user_b )
INNER JOIN users ON (wall.from_user_id = users.id)
WHERE not exists (select * from blocklist where users.id = blocked_id AND user_id = 1) and wall.wall_type IN ('home', 'profile', 'topro') AND (
(friendship.user_a = 1 and friendship.user_b = wall.from_user_id)
or
(friendship.user_a = wall.from_user_id and friendship.user_b = 1) or (wall.user_id_of_wall = 1 or type_id = 1 or from_user_id = 1))
GROUP BY wall_id
ORDER BY date DESC LIMIT 10
[EDIT] Use IN for fixed values (wall_type)...
Altri suggerimenti
always use WITH (NOLOCK) on read-only queries!
also, please remove all your paranthesis on your JOIN clause, did you copy and paste this from MS Access?