如何计算表格的高度分数

Question

   SELECT * FROM `result` Where R_TestID=16 AND R_IsCorrect='yes'.

实际上我想要这个where clasue并且还要计算更多重复的R_UserID。 一揽子谢谢

Answer 1

您可以执行此分组，命令desc和限制1

 select count(*) as my_val from `result`  Where R_TestID=16 AND R_IsCorrect='yes'
 group by R_UserID
 order by my_val desc 
 limit 1

Answer 2

SELECT count(distinct(R_UserID)) FROM `result` Where R_TestID=16 AND R_IsCorrect='yes'.

Answer 3

CREATE TABLE IF NOT EXISTS `result` (
  `R_UserID` int(10) NOT NULL,
  `R_TestID` int(10) NOT NULL,
  `R_IsCorrect` varchar(10) NOT NULL
) ENGINE=InnoDB DEFAULT CHARSET=latin1;


INSERT INTO `result` (`R_UserID`, `R_TestID`, `R_IsCorrect`) VALUES
(1, 16, 'yes'),
(1, 16, 'yes'),
(2, 16, 'yes'),
(2, 16, 'yes'),
(2, 16, 'yes'),
(2, 16, 'yes'),
(2, 16, 'yes'),
(2, 16, 'yes');


SELECT R_UserID, COUNT(*) AS user_count
FROM `result` 
WHERE R_TestID=16 AND R_IsCorrect='yes' 
GROUP BY R_UserID
ORDER BY user_count DESC;

输出

R_UserID   user_count 
2          6
1          2