带条件的左联接查询

Question

I have a query that LEFT JOINS another table to group rows. I am trying to only select records from the first table "googleimage" where the user_id is a certain number. (user_id is a column in "googleimage" table.

SELECT g.*
FROM googleimage g
LEFT JOIN (SELECT image_id, COUNT(*) AS cnt
FROM googleimagefound WHERE status = 0
GROUP BY image_id) gf ON gf.image_id = g.id
ORDER BY  COALESCE(cnt, 0) DESC");

I have tried adding a new ON statement beiside the

gf ON gf.image_id = g.id

I have also tried changing

SELECT g.*
FROM googleimage g

to

SELECT g.*
FROM googleimage WHERE user_id = 1 g

but none of them seem to work, any help will be appriciated

Answer 1

Try changing you query a bit like below

SELECT g.*
FROM googleimage g
LEFT JOIN (SELECT image_id, COUNT(*) AS cnt
FROM googleimagefound WHERE status = 0
GROUP BY image_id) gf ON gf.image_id = g.id
WHERE g.user_id = 1 <-- add this condition
ORDER BY  COALESCE(gf.cnt, 0) DESC;