Question

我想在设定范围内找到最小日期，例如下面我想找到每个学生的最短申请日期。 MySQL不接受此查询。

SELECT MIN(applications.date) AS 'D', students.name
FROM applications, students
WHERE applications.student_id = students.id AND
D BETWEEN '2016-05-01' AND '2016-05-31'
GROUP BY students.id

Answer 1

试试这个，只需使用where子句中的表列而不是别名;）

SELECT *
FROM (
    SELECT MIN(applications.date) AS 'D', students.name
    FROM applications, students
    WHERE applications.student_id = students.id
    GROUP BY students.id
) tmp
WHERE D BETWEEN '2016-05-01' AND '2016-05-31'

Answer 2

您不能使用where子句对来自min()的聚合函数的结果应用过滤器，而是可以使用having子句

SELECT MIN(a.date) AS `D`,s.id,s.name
FROM applications a
JOIN students s ON a.student_id = s.id 
GROUP BY s.id,s.name
HAVING `D` >= '2016-05-01' AND `D` <= '2016-05-31'

mysql搜索范围内的min（日期）

2 个答案: