CODEWITHSUNDEEP
mysqlsql
Oscar Reyes
Oscar Reyes

Reputation: 4352

SQL: count rows from 3rd table

I have 3 tables, the first table is the account_has_account1 where i store the relation between accounts and it's columns are account_id, account_id1, status where account_id is the account doing following to account_id1 and status is an enum type with values active, inactive where active indicates if the account is actually following, if it's inactive, then account stopped following.

the second table is named account_has_photos which i store the photos one account has stored in the database, so it's columns are account_id, photos_id, so i need this table to get all photos from one account which another account is following.

But all these have messages posted on them, and here is where the 3rd table comes which is named photos_has_message_photos, from this table i only need a count of all posted messages in one photo, the columns are photos_id, message_photos_id

for now my query is this:

SELECT account_has_photos.photos_id as id, "photos" as type, account_has_photos.update_at, account_has_photos.account_id
FROM account_has_account1 
    JOIN account_has_photos 
        ON (account_has_photos.account_id = account_has_account1.account_id1 AND account_has_photos.type_id = 17)
WHERE account_has_account1.account_id = 7 AND account_has_account1.`status` = "Active"

it shows all photos from accounts on which account id 7 is following, but on my attempts on getting the total messages have failed, i thought on doing an INNER JOIN like this:

INNER JOIN (
        SELECT photos_has_message_photos.photos_id, count(photos_has_message_photos.photos_id) as total
        FROM photos_has_message_photos
    ) posts
        ON(posts.photos_id = account_has_photos.photos_id)

and then i select from main posts.total, but it does not show any row, not even the photos, the result is empty at this point and i have no idea why and what to do.

the complete query is like this:

SELECT account_has_photos.photos_id as id, "photos" as type, account_has_photos.update_at, account_has_photos.account_id, posts.total
FROM account_has_account1 
    JOIN account_has_photos 
        ON (account_has_photos.account_id = account_has_account1.account_id1 AND account_has_photos.type_id = 17)
    INNER JOIN (
        SELECT photos_has_message_photos.photos_id, count(photos_has_message_photos.photos_id) as total
        FROM photos_has_message_photos
    ) posts
        ON(posts.photos_id = account_has_photos.photos_id)
WHERE account_has_account1.account_id = 7 AND account_has_account1.`status` = "Active"

again, i only need a total of rows which are messages from each photos found

Upvotes: 0

Views: 82

Answers (1)

Mahesh Madushanka
Mahesh Madushanka

Reputation: 3008

Try this query updated inner select 

 SELECT ahp.photos_id as id, "photos" as type, ahp.update_at, ahp.account_id,posts.total
FROM account_has_account1 
    JOIN account_has_photos 
        ON (ahp.account_id = account_has_account1.account_id1 AND ahp.type_id = 17) INNER JOIN (
        SELECT phmp.photos_id, count(*) as total FROM photos_has_message_photos GROUP BY phmp.photos_id
    ) posts
        ON(posts.photos_id = ahp.photos_id) WHERE account_has_account1.account_id = 7 AND account_has_account1.`status` = "Active"

Upvotes: 1

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