Question

我有一个代码，可以输出一长串每个名称的工单总数，并按总数，名称和数量进行排序：

;with cte as (
SELECT [Name],
        [Emergency],
        count([Emergency]) as [CountItem]
FROM tableA
GROUP BY [Name], [Emergency])

select Name,[Emergency],[Count],SUM([CountItem]) OVER(PARTITION BY Name) as Total from cte
order by Total desc, Name, [CountItem] desc

但我只想获得总数最多的前10个名称，如下所示：

+-------+-------------------------------+-------+-------+
| Name  |           Emergency           | Count | Total |
+-------+-------------------------------+-------+-------+
| PLB   | No                            |     7 |    15 |
| PLB   | No Hot Water                  |     4 |    15 |
| PLB   | Resident Locked Out           |     2 |    15 |
| PLB   | Overflowing Tub               |     1 |    15 |
| PLB   | No Heat                       |     1 |    15 |
| GG    | Broken Lock - Exterior        |     6 |     6 |
| BOA   | Broken Lock - Exterior        |     2 |     4 |
| BOA   | Garage Door not working       |     1 |     4 |
| BOA   | Resident Locked Out           |     1 |     4 |
| 15777 | Smoke  Alarm not working      |     3 |     3 |
| FP    | No air conditioning           |     2 |     3 |
| FP    | Flood                         |     1 |     3 |
| KB    | No electrical power           |     2 |     3 |
| KB    | No                            |     1 |     3 |
| MEM   | Noise Complaint               |     3 |     3 |
| ANG   | Parking Issue                 |     2 |     2 |
| ALL   | Smoke  Alarm not working      |     2 |     2 |
| AAS   | No air conditioning           |     1 |     2 |
| AAS   | Toilet - Clogged (1 Bathroom) |     1 |     2 |
+-------+-------------------------------+-------+-------+

注意：我不追求唯一值。正如您从上面的示例中看到的那样，它从一个很长的表中获得前10名。

我想为每个名称分配一个行ID，以便上面的所有PLB的行ID为1，GG = 2，BOA = 3，...

因此，在我的最终选择中，我只会添加where子句where row id <= 10。我已经尝试过ROW_NUMBER() OVER(PARTITION BY Name ORDER BY Name)，但它会为其遇到的每个唯一名称分配1。

Answer 1

您可以尝试以下方法：

    ;with cte as (
    SELECT [Name],
            [Emergency],
            count([Emergency]) as [CountItem]
    FROM tableA
    GROUP BY [Name], [Emergency]),
    ct as (
    select Name,[Emergency],[Count],SUM([CountItem]) OVER(PARTITION BY PropertyName) as Total from cte
    ),
    ctname as (
    select dense_rank() over ( order by total, name ) as RankName, Name,[Emergency],[Count], total from ct )
    select * from ctname where rankname < 11

Answer 2

假设查询为MySQL，则需要使用LIMIT

algorithmic complexity attacks

如果查询是SQL，则需要使用TOP

https://dev.mysql.com/doc/refman/5.5/en/limit-optimization.html

根据列值获得前10名

2 个答案: