Question

我在MS访问中有一个表有2个字段（payroll和absenceReason）。每个缺席实例都有一条记录。

我正在尝试编写SQL查询以返回每个人最常见的缺席原因。我确信有一种简单的方法可以做到这一点，但我似乎无法得到它。我试过写下面的查询：

SELECT payroll, reason, max(count)
FROM
(
SELECT payroll, reason, count(reason) as count
FROM table1
GROUP BY payroll, reason
) 
GROUP BY payroll, reason

但这会让每个人都有理由。如果我从GROUP BY子句中删除原因，那么它不起作用，因为我没有在select部分中聚合原因。谁能指出我哪里出错？

由于

Answer 1

一种方法使用having：

SELECT payroll, reason, count(reason) as count
FROM table1 as t1
GROUP BY reason, payroll
HAVING t1.reason = (SELECT TOP 1 tt1.reason
                    FROM table1 as tt1
                    WHERE tt1.payroll = t1.payroll
                    GROUP BY tt1.reason
                    ORDER BY COUNT(*) DESC, tt1.reason
                   );

获取每组的最大数量

1 个答案: