CODEWITHSUNDEEP
sqldatabasepostgresql
cola
cola

Reputation: 12466

Need a sql query to find posts with most commented order by comments number/count DESC

\d posts

                                   Table "public.posts"
   Column    |          Type          |                     Modifiers                      
-------------+------------------------+----------------------------------------------------
 id          | integer                | not null default nextval('posts_id_seq'::regclass)
 title       | character varying(100) | not null
 content     | character varying(500) | not null
 created_at  | date                   | 
 updated_at  | date                   | 
 tags        | character varying(55)  | not null default '50'::character varying
 category_id | integer                | not null default 1
Indexes:
    "posts_pkey" PRIMARY KEY, btree (id)

\d comments

                                   Table "public.comments"
   Column   |          Type          |                       Modifiers                       
------------+------------------------+-------------------------------------------------------
 id         | integer                | not null default nextval('comments_id_seq'::regclass)
 post_id    | integer                | not null
 name       | character varying(255) | not null
 email      | character varying(255) | not null
 content    | character varying(500) | not null
 created_at | date                   | 
 updated_at | date                   | 
Indexes:
    "comments_pkey" PRIMARY KEY, btree (id)

I need a sql query to find posts with most commented. How can I do it?

Upvotes: 2

Views: 1755

Answers (2)

Glenn
Glenn

Reputation: 9160

  SELECT id, title, comment_count
    FROM ( SELECT p.id, p.title, COUNT(c.id) AS comment_count
             FROM posts p
                 ,comments c
             WHERE c.post_id = p.id
             GROUP BY p.id, p.title
             ORDER BY 3 DESC ) x
    LIMIT 1;

Upvotes: 2

Maess
Maess

Reputation: 4156

in tsql you would do the following, I hope it steers you in the right direction 

SELECT
         p.id,
         c.postcount
    FROM posts as p
    INNER JOIN (
                  SELECT
                         post_id,
                         count(*) AS postcount
                  FROM comments
                  GROUP BY post_id
               ) as c
           on p.id = c.post_id

    Order by c.postcount desc

Upvotes: 4

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