优化mysql子查询语句

Question

I'm making a community shares 'creepy pasta'. My query takes 133ms now, but I wanna make the query faster. just recommending a keyword is enough.

here are my tables.

Column Description:

'cp_id' means creepypasta's id.

'session_id' is something like writer.

'creepy' means how creepy the creepy pasta is. when 'creepy' is 0, it's not creepy story. but when that is 1, it's creepy.

 - creepypastas: id, alias, created_at, modified_at, title, content, session_id
 - creepypasta_comments: id, cp_id, created_at, content, session_id
 - creepy_points: id, cp_id, creepy, session_id

and here's my SQL query.

SELECT id, alias, created_at, modified_at, title, content, session_id, 
(SELECT COALESCE(SUM(case creepy when 1 then 1 else 0 end), 0) FROM 
creepy_points c WHERE creepypastas.id = c.cp_id) AS creepy_count, 
(SELECT COALESCE(SUM(case creepy when 0 then 1 else 0 end), 0) FROM 
creepy_points c WHERE creepypastas.id = c.cp_id) AS not_creepy_count, 
(SELECT COUNT(c.id) FROM creepypasta_comments c WHERE creepypastas.id = 
c.cp_id) AS comment_count 
FROM creepypastas ORDER BY created_at DESC

Answer 1

对于您的查询，您可以在creepy_points(cp_id, creepy)上添加索引：

create index idx_creepypoints_cpid_creepy on creepy_points(cpid, creepy);