我有以下查询。
SELECT
SUM(
marks_obtained_written + marks_obtained_oral + marks_obtained_classwork
),
FIND_IN_SET(
SUM(
marks_obtained_written + marks_obtained_oral + marks_obtained_classwork
),
(SELECT
GROUP_CONCAT(summarks
ORDER BY summarks DESC)
FROM
(SELECT
SUM(
marks_obtained_written + marks_obtained_oral + marks_obtained_classwork
) AS summarks
FROM
results
GROUP BY student_id) sm)
) AS rank
FROM
results
WHERE student_id = ".$student_id."
AND exam_year = ".$year."
AND exam_id = ".$exam."
AND results.class_id = ".$class_id."
AND section_id = ".$section_id."
仅当我的结果表中有一项考试时,此查询才适合我。 当有更多考试时,此查询会计算所有考试的分数并将排名返回给我。但是,如果我只需要一项考试的学生排名,我需要将 exam_id 放入查询中,当我这样做时,查询将返回 0 作为学生排名。
在上图中,我得到了无效的第 0 个位置。但是如果我删除 exam_id 条件,那么我会得到正确的排名,但问题是它对所有我不想要的已输入考试的分数进行求和,因为我需要排名具体考试。
所以请有人告诉我应该将 exam_id 条件放在查询中的哪里。
最佳答案
尝试将 exam_id 也放入您的子查询中。
(SELECT
GROUP_CONCAT(summarks
ORDER BY summarks DESC)
FROM
(SELECT
SUM(
marks_obtained_written + marks_obtained_oral + marks_obtained_classwork
) AS summarks
FROM
results WHERE exam_id = ?
GROUP BY student_id
关于php - mysql 获取学生考试排名,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/43178310/