mysql - 还选择倒数第二个mysql值

Question

我正在尝试从表格中选择最大里程和第二大里程。

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

基本上做一个正常的查询，并按降序排序并限制为2。类似下面的东西（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

一种快速而肮脏的方法是排序

ORDER BY oil.mileage DESC

接着

LIMIT 0, 2

Answer 3

试试这个：如果你只需要倒数第二个里程然后使用这个::

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

如果您同时需要最大值和倒数第二个，请使用此::

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