Question

我试图从桌子上选择最大里程数和第二大里程数。

到目前为止我的查询是：

SELECT oil.empid, oil.mileage, users.name, oil.date, MAX(oil.mileage)
FROM oil, users
WHERE oil.empid = users.empid
GROUP BY oil.empid
ORDER BY oil.mileage

但是这会选择输入的第一个里程和最大值

我如何改变它以获得第二大里程？

Answer 1

基本上做一个普通的查询并按降序排序并将其限制为2.如下所示（未测试）

SELECT
    oil.empid,
    oil.mileage,
    users.name,
    oil.date
FROM oil, users
WHERE (oil.empid = users.empid)
GROUP BY oil.empid
ORDER BY oil.mileage DESC
LIMIT 2

Answer 2

试试这个：如果你只需要倒数第二个里程，那么使用这个::

SELECT oil.empid, oil.mileage, users.name, oil.date, MAX(oil.mileage)
FROM oil, users
WHERE oil.empid = users.empid
GROUP BY oil.empid
ORDER BY oil.mileage desc
limit 1, 1

如果你同时需要max和second second，请使用::

SELECT oil.empid, oil.mileage, users.name, oil.date, MAX(oil.mileage)
FROM oil, users
WHERE oil.empid = users.empid
GROUP BY oil.empid
ORDER BY oil.mileage desc
limit 2

Answer 3

快速而肮脏的方法是排序

ORDER BY oil.mileage DESC

然后

LIMIT 0, 2

同时选择倒数第二个mysql值

3 个答案: