Return all rows from sub-query SQL?

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

在子选择之前使用IN代替'='。

Answer 3

在使用替代的==

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