Question

我有一个表来存储调查的答案，我试图查询mysql告诉我某个调查是否被答案字段= 16或20的人回答

我有以下的mysql语句

SELECT DISTINCT(submissionID) as submissionID FROM answer 
WHERE EXISTS (
    SELECT *
    FROM answer
    WHERE submissionID = submissionID AND (answer = '16' OR answer = '20')

)

在这里编辑

抱歉，我不认为我的问题是正确的，所以这是我的表结构：

CREATE TABLE IF NOT EXISTS `answer` (
  `aID` int(11) NOT NULL AUTO_INCREMENT,
  `sID` int(11) NOT NULL,
  `qtID` int(11) NOT NULL,
  `answer` text NOT NULL,
  `userIP` text NOT NULL,
  `submissionID` int(11) NOT NULL,
  PRIMARY KEY (`aID`)
) ENGINE=MyISAM  DEFAULT CHARSET=latin1 AUTO_INCREMENT=422 ;

aID是给出的每个答案的唯一ID。
sID是调查ID（因为我可能有不止一次调查）
qtID是questionsID值
answer是用户对此调查的qtID给出的答案
userIP可自我解释
submissionID是每次提交的ID

所以我知道在这个表中有5个唯一的submitID，但只有一个submssionID答案字段= 16和20

Answer 1

我认为您的查询过于复杂，请尝试以下方法：

SELECT DISTINCT submissionID FROM answer 
WHERE answer IN ('16', '20');

Answer 2

“我的故障是什么？”

将子查询与外部查询相关联的条件：

submissionID = submissionID

总是如此。我不认为你真的需要它，为什么不写：

SELECT DISTINCT submissionID 
FROM answer 
WHERE answer = '16' OR answer = '20'

但是，我觉得你没有给我们所有的信息。例如，我在原始查询中看不到任何限制特定问题的答案。如果调查只有一个问题，那当然是可能的，但我觉得这不是你的意思。精心...

Answer 3

我认为您需要在子句中的一个或另一个中为答案表添加别名。像这样......

SELECT DISTINCT(submissionID) as submissionID FROM answer a 
WHERE EXISTS (
    SELECT *
    FROM answer
    WHERE submissionID = a.submissionID AND (answer = '16' OR answer = '20')

)

Answer 4

这是您的原始查询

SELECT DISTINCT(submissionID) as submissionID FROM answer 
WHERE EXISTS (
    SELECT *
    FROM answer
    WHERE submissionID = submissionID AND (answer = '16' OR answer = '20')

)

您应该为表添加别名以将它们关联起来

SELECT DISTINCT(submissionID) as submissionID FROM answer B
WHERE EXISTS (
    SELECT *
    FROM answer A
    WHERE A,submissionID = B.submissionID AND (answer = '16' OR answer = '20')

)

带内部查询的mysql

4 个答案: