Question

我有一个表'wordstyped'，其中包含'idBook'，'guidUser'，'bookmarkLetter'，'letter'，'attemptWrong'和'isCorrect'。

idBook  guidUser  bookmarkLetter  letter  attemptWrong   isCorrect
-------------------------------------------------------------------
1       1         100             a       2              0
1       1         100             a       3              0
1       1         100             a       3              1
1       1         101             b       6              0
1       1         101             b       2              0
2       2         101             b       3              0
2       3         152             d       7              0
3       3         153             e       2              0

我想选择所有记录，它们的所有字段都包含最大数量的“ attemptWrong”，但三元组分别为“ idBook”，“ guidUser”和“ bookmarkLetter”。我已经通过此查询完成了

SELECT DISTINCT w1.bookmarkletter, w1.attemptsWrong
FROM wordstyped w1 INNER JOIN ( SELECT bookmarkLetter, guidUser, idBook, 
MAX(attemptsWrong) AS maxAttemptsWrong 
FROM wordstyped 
GROUP BY bookmarkLetter, guidUser, idBook ) w2 
ON w1.bookmarkLetter = w2.bookmarkLetter AND w1.guidUser = w2.guidUser 
AND w1.guidUser = '1' 
AND w1.idBook ='1'
AND w1.attemptsWrong = w2.maxAttemptsWrong AND w1.bookmarkLetter >=0
AND w1.bookmarkLetter <=200 ORDER BY `w1`.`bookmarkletter` ASC

就像这个小提琴http://sqlfiddle.com/#!9/238794/2

现在，我也要选择'isCorrect'，如果至少一个记录的ha值为isCorrect = 1，则选择值为1；如果所有记录的值为0，则选择0。

在示例情况下，如果我将w1.isCorrect添加到第一个select语句喜欢

SELECT DISTINCT w1.bookmarkletter, w1.attemptsWrong, w1.isCorrect
FROM wordstyped w1 INNER JOIN ( SELECT bookmarkLetter, guidUser, idBook, 
MAX(attemptsWrong) AS maxAttemptsWrong 
FROM wordstyped 
GROUP BY bookmarkLetter, guidUser, idBook ) w2 
ON w1.bookmarkLetter = w2.bookmarkLetter AND w1.guidUser = w2.guidUser 
AND w1.guidUser = '1' 
AND w1.idBook ='1'
AND w1.attemptsWrong = w2.maxAttemptsWrong AND w1.bookmarkLetter >=0
AND w1.bookmarkLetter <=200 ORDER BY `w1`.`bookmarkletter` ASC

（http://sqlfiddle.com/#!9/238794/1），这组记录

idBook  guidUser  bookmarkLetter  letter  attemptWrong   isCorrect
-------------------------------------------------------------------
1       1         101             b       6              0
1       1         101             b       2              0
2       2         101             b       3              0

正确返回

bookmarkLetter    attemptWrong    isCorrect
-------------------------------------------------------------------
101               6               0

这组记录

idBook  guidUser  bookmarkLetter  letter  attemptWrong   isCorrect
-------------------------------------------------------------------
1       1         100             a       2              0
1       1         100             a       3              0
1       1         100             a       3              1

返回

bookmarkLetter    attemptWrong    isCorrect
-------------------------------------------------------------------
100               3               0
100               3               1

代替

bookmarkLetter    attemptWrong    isCorrect
-------------------------------------------------------------------
100               3               1

如何获得第二个结果？

编辑：我有isCorrect 1的情况总是像示例中一样发生，即我有两条带有tryWrong的记录是最大值，一个有isCorrect = 0的记录和一个具有isCorrect = 1的记录

Answer 1

尝试使用汇总和分组依据

http://sqlfiddle.com/#!9/238794/4

SELECT w1.bookmarkletter, max(w1.attemptsWrong), max(w1.isCorrect) 
  FROM wordstyped w1 INNER JOIN 
  ( SELECT bookmarkLetter, guidUser, idBook, MAX(attemptsWrong) AS maxAttemptsWrong 
    FROM wordstyped 
    GROUP BY bookmarkLetter, guidUser, idBook ) w2 
ON w1.bookmarkLetter = w2.bookmarkLetter AND w1.guidUser = w2.guidUser 
AND w1.guidUser = '1' 
AND w1.idBook ='1'
AND w1.attemptsWrong = w2.maxAttemptsWrong AND w1.bookmarkLetter >=0
AND w1.bookmarkLetter <=200 
group by w1.bookmarkletter
ORDER BY `w1`.`bookmarkletter` ASC

mysql-如何在字段中选择具有0或1值的记录集，仅在值存在的情况下才具有值1的记录，在mysql中？

1 个答案: