从子查询SQL返回所有行？

Question

现在，我编写了查询SQL以获取受第一个查询限制的行：

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

当我尝试执行此查询时，我得到：

#1242 - Subquery returns more than 1 row 

如何解决这个问题？ 因此，我需要从子查询中获取所有行。

如果我想返回一行-我需要使用GROUP BY ，但这不是解决方案

修改后的查询：

    SELECT a.idCommentToArticle FROM 
commenttoarticle a WHERE a.CommentToArticlePID IN 
(SELECT idCommentToArticle FROM commenttoarticle b) ORDER BY a.idCommentToArticle DESC LIMIT 3

转储表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);

结果我需要：

这是sqlfiddle的示例：sqlfiddle.com/ # !2/ dbd82a/1我需要为每个第一个查询（如果存在）获取最后3行，且无限制COMMENTTOARTICLEPID 。 例如，我需要获得IDCOMMENTTOARTICLE: 58, 57, 56, 52行

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

使用IN代替=因为查询返回很多值：

SELECT * FROM commenttoarticle a 
WHERE a.idCommentToArticle IN (
    SELECT CommentToArticlePID 
    FROM commenttoarticle b) 
ORDER BY a.idCommentToArticle DESC LIMIT 3 

Answer 5

您可以在子查询或主查询或两者中使用限制。 如果只需要3个结果，则在主查询中添加限制

SELECT * FROM commenttoarticle a WHERE a.idCommentToArticle IN (SELECT CommentToArticlePID FROM commenttoarticle b) ORDER BY a.idCommentToArticle DESC LIMIT 3 

如果您想在子查询中获得3个结果，则将是这样

SELECT * FROM commenttoarticle a WHERE a.idCommentToArticle IN (SELECT CommentToArticlePID FROM commenttoarticle b LIMIT 3) ORDER BY a.idCommentToArticle DESC

如果你两个都想要

SELECT * FROM commenttoarticle a WHERE a.idCommentToArticle IN (SELECT CommentToArticlePID FROM commenttoarticle b LIMIT 3) ORDER BY a.idCommentToArticle DESC LIMIT 3 

Answer 6

我认为您的子查询返回的行数超过1，因此将您的“ =”替换为“ IN”。 像这样...

SELECT * FROM commenttoarticle a 
WHERE a.idCommentToArticle IN (SELECT CommentToArticlePID FROM commenttoarticle b) 
ORDER BY a.idCommentToArticle DESC LIMIT 3