Return all rows from sub-query SQL? - mysql

Question

Now I wrote query SQL for getting rows limited by first query:
SELECT * FROM commenttoarticle a
WHERE a.idCommentToArticle = (SELECT CommentToArticlePID FROM commenttoarticle b)
ORDER BY a.idCommentToArticle DESC LIMIT 3
When I try to execute this query, I get:
#1242 - Subquery returns more than 1 row
How to resolve this issue? So, I need get all rows from sub-query.
If I want return one row - I need use GROUP BY, but it is not solution
Modified query:
SELECT a.idCommentToArticle FROM
commenttoarticle a WHERE a.CommentToArticlePID IN
(SELECT idCommentToArticle FROM commenttoarticle b) ORDER BY a.idCommentToArticle DESC LIMIT 3
Dump table commenttoarticle:
CREATE TABLE IF NOT EXISTS `commenttoarticle` (
`idCommentToArticle` int(11) NOT NULL AUTO_INCREMENT,
`CommentToArticleTime` int(11) NOT NULL,
`CommentToArticleIdArticle` int(11) NOT NULL,
`CommentToArticleComment` text NOT NULL,
`CommentToArticleIdUser` int(11) NOT NULL,
`CommentToArticlePID` int(11) NOT NULL,
PRIMARY KEY (`idCommentToArticle`),
UNIQUE KEY `idCommentToArticle_UNIQUE` (`idCommentToArticle`)
) ENGINE=MyISAM DEFAULT CHARSET=utf8 AUTO_INCREMENT=59 ;
--
-- Дамп данных таблицы `commenttoarticle`
--
INSERT INTO `commenttoarticle` (`idCommentToArticle`, `CommentToArticleTime`, `CommentToArticleIdArticle`, `CommentToArticleComment`, `CommentToArticleIdUser`, `CommentToArticlePID`) VALUES
(29, 0, 11, 'продажам?\nИнтересует не мега-звезда, а именно предметный, руками умеющий продавать сам и помогающий выстраивать это бизнесам.', 459, 0),
(30, 0, 11, '2', 459, 0),
(31, 0, 11, '3', 459, 0),
(36, 0, 11, '3.1', 459, 31),
(37, 1413822798, 11, 'also facing that prob. on the plteform of win 7', 459, 29),
(38, 0, 11, ' here i dont have internet connection.. #Samint Sinha thanks ill check it out maybe tomorrow.', 459, 29),
(39, 0, 11, ' Select max id and you will have dhe last row returned', 459, 29),
(32, 0, 11, '4', 459, 0),
(44, 1414354324, 11, 'How to do', 456, 29),
(45, 1414354469, 11, 'sfsfsf', 456, 29),
(46, 1414354708, 11, 'dddd', 456, 29),
(47, 1414357761, 11, 'sfsfs', 456, 0),
(57, 1414370833, 39, 'kkkppppppp', 456, 0),
(49, 1414358233, 11, 'VSF\nSFSF', 456, 0),
(50, 1414359589, 11, 'How to do', 456, 0),
(51, 1414359660, 11, 'sfsfsdf', 456, 0),
(52, 1414361057, 11, 'SDFSF', 456, 0),
(53, 1414364023, 11, 'dsfdsjfsifmsi', 456, 0),
(54, 1414364031, 11, 'sdfdskjfnskf', 456, 52),
(55, 1414364034, 11, 'sdfdskjfnskf', 456, 52),
(56, 1414364044, 11, 'fndsdfnsofosfi', 456, 52),
(58, 1414370841, 39, 'dfgdfgdgdgdgdgdfgdgdfg', 456, 0);
Result what I need:
Here is example at sqlfiddle: sqlfiddle.com/#!2/dbd82a/1 I need get last 3 rows with a unlimited COMMENTTOARTICLEPID for each first query, if exists. In example, I need get rows with IDCOMMENTTOARTICLE: 58, 57, 56, 52

Answer 1

SELECT a.*
FROM commenttoarticle a
JOIN commenttoarticle b
ON b.CommentToArticlePID = a.idCommentToArticle
ORDER
BY a.idCommentToArticle DESC
LIMIT 3

Answer 2

use IN instead of '=' before sub-select.

Answer 3

USe in instead of ==
SELECT * FROM commenttoarticle a WHERE a.idCommentToArticle in (SELECT CommentToArticlePID FROM commenttoarticle b) ORDER BY a.idCommentToArticle DESC LIMIT 3

Answer 4

Use IN instead of = because your query returns lot of values:
SELECT * FROM commenttoarticle a
WHERE a.idCommentToArticle IN (
SELECT CommentToArticlePID
FROM commenttoarticle b)
ORDER BY a.idCommentToArticle DESC LIMIT 3

Answer 5

You can use limit in both sub query or main query or both.
If you need only 3 result then add limit at main query
SELECT * FROM commenttoarticle a WHERE a.idCommentToArticle IN (SELECT CommentToArticlePID FROM commenttoarticle b) ORDER BY a.idCommentToArticle DESC LIMIT 3
If you want 3 result at sub query then it will be like this
SELECT * FROM commenttoarticle a WHERE a.idCommentToArticle IN (SELECT CommentToArticlePID FROM commenttoarticle b LIMIT 3) ORDER BY a.idCommentToArticle DESC
If you want both
SELECT * FROM commenttoarticle a WHERE a.idCommentToArticle IN (SELECT CommentToArticlePID FROM commenttoarticle b LIMIT 3) ORDER BY a.idCommentToArticle DESC LIMIT 3

Answer 6

I am thinking that your subquery returns more than 1 row hence replace your "=" with "IN". Like this...
SELECT * FROM commenttoarticle a
WHERE a.idCommentToArticle IN (SELECT CommentToArticlePID FROM commenttoarticle b)
ORDER BY a.idCommentToArticle DESC LIMIT 3