Question

这是我的表：

ID UserID Client Time(timestamp)

1  25     Acer   2017-09-13 09:09:13
2  21     Lenovo 2017-09-13 12:09:32
3  20     HP     2017-09-13 14:04:26
4  21     Dell   2017-09-13 17:04:23
5  25     Apple  2017-09-13 17:09:46
.
.
.

我希望首先按时间戳排序结果，获取前5条记录，然后按照用户ID排序

ID UserID Client Time(timestamp)
5  25     Apple  2017-09-13 17:09:46
1  25     Acer   2017-09-13 09:09:13
4  21     Dell   2017-09-13 17:04:23
2  21     Lenovo 2017-09-13 12:09:32
3  20     HP     2017-09-13 14:04:26

我试过这个查询

select * from table order by time Desc, UserID LIMIT 5;

但它似乎没有用，相反我得到了这个结果

ID UserID Client Time(timestamp)
5  25     Apple  2017-09-13 17:09:46
4  21     Dell   2017-09-13 17:04:23
3  20     HP     2017-09-13 14:04:26
2  21     Lenovo 2017-09-13 12:09:32
1  25     Acer   2017-09-13 09:09:13

我不确定我哪里出错了。

Answer 1

您可以尝试这样做：

SELECT * FROM
(
    SELECT *
    FROM table
    ORDER BY time DESC
    LIMIT 5
) AS firstusers
ORDER BY UserID

Answer 2

行。您需要获取按时间戳排序的前5个记录，并按userID重新排序。这是代码：

SELECT * FROM (
    SELECT* FROM 
    table1 
    ORDER BY time DESC 
    LIMIT 5) firstfive 
ORDER BY UserID DESC

Answer 3

应改为order by UserID DESC, time Desc：

select * 
from table1 order by  UserID DESC, time Desc;

demo

这将为您提供所需的订单：

| ID | UserID | Client |                 Time |
|----|--------|--------|----------------------|
|  5 |     25 |  Apple | 2017-09-13T17:09:46Z |
|  1 |     25 |   Acer | 2017-09-13T09:09:13Z |
|  4 |     21 |   Dell | 2017-09-13T17:04:23Z |
|  2 |     21 | Lenovo | 2017-09-13T12:09:32Z |
|  3 |     20 |     HP | 2017-09-13T14:04:26Z |

Answer 4

您需要内联视图，首先按time获取5行，然后UserID

SELECT * FROM
(
    SELECT *
    FROM table
    ORDER BY time DESC
    LIMIT 5
)
ORDER BY UserID DESC

因此，上面的查询嵌套了select，它将首先执行，并按time降序排列5行。然后，我们将使用此结果集进行外部查询，并按UserID

对行进行排序

按一列排序，然后按另一列排序

4 个答案: