在MySQL中获取DISTINCT ID

Question

I have a table structure like this:

Comments table
id      review_id    user_id  created     comments deleted
1       10           28       2011-10-12  "hi"     0
2       11           28       2011-10-13  "yo"     0
3       10           28       2011-10-15  "bye"    0

I want to get the latest comment from each review sorted by created DESC. So I have something like this:

SELECT DISTINCT review_id, 'comments' as type FROM comments as MyTable WHERE 
user_id=28 AND deleted=0 ORDER BY created DESC LIMIT 30

So in the above table I want the rows for id = 3 and then id = 2 returned.

Answer 1

Example Query:

http://data.stackexchange.com/stackoverflow/s/2143/getting-distinct-ids-in-mysql

SELECT id,comment
FROM comments
WHERE id IN (
    SELECT MAX(id)
    FROM comments
    WHERE user_id=28 AND deleted=0
    GROUP BY review_id )
ORDER BY created DESC

Answer 2

Please integrate this code in your code.

Table data:

id      review_id    user_id  created     comments deleted
1       10           28       2011-10-12  "hi"     0
2       11           28       2011-10-13  "yo"     0
3       10           28       2011-10-15  "bye"    0

Run query:

SELECT DISTINCT id, review_id, 'comments' AS TYPE 
FROM mytable
WHERE user_id = 28
AND deleted = 0
AND id = (
  SELECT max( id )
  FROM mytable 
)

Result:

id  review_id    TYPE
3   10       comments