Question

我有一张桌子：

| LastName | FirstName | Title                | isdefault |
+----------+-----------+----------------------+-----------+
| Davolio  | Nancy     | Sales Representative | 1         |
| Fuller   | Andrew    | Vice President, Sales| 1         |
| Fuller   | Andrew    | Vice President, Sales| 0         |
| Fuller   | Andrew    | Vice President, Sales| 0         |
| Leverling| Janet     | Sales Representative | 0         |
| Leverling| Janet     | Sales Representative | 0         |
| Leverling| Janet     | Sales Representative | 0         |

在SQL Server数据库中。

我的查询是：

SELECT 
    LastName, FirstName, Title, isdefault 
FROM 
    Employees

我希望选择相同的记录，isdefault = 0。所以我的新输出应该是：

| LastName | FirstName | Title                | isdefault |
+----------+-----------+----------------------+-----------+
| Leverling| Janet     | Sales Representative | 0         |
| Leverling| Janet     | Sales Representative | 0         |
| Leverling| Janet     | Sales Representative | 0         |

我尝试使用GROUP BY：

 SELECT 
    LastName, FirstName, Def_flag 
 FROM 
    Employees 
 WHERE 
    Def_flag = 0 
 GROUP BY 
    LastName, FirstName, Def_flag

但结果并不能让我满意，因为安德鲁·富勒的记录也进入了表格。

我如何更改查询？

问候，亚历山大。

Answer 1

您的意思是，Def_flag的所有条目都为0的员工<？p>

select
    LastName,
    FirstName, 
    Def_flag 
from (
    select
        ROW_NUMBER() OVER (
            PARTITION BY
                LastName,FirstName
            ORDER BY
                Def_flag DESC
        ) i
        LastName,
        FirstName, 
        Def_flag 
    FROM Employees
) T
where
    i = 1 and
    Def_flag = 0

Answer 2

假设isdefault有点，你可以这样做。否则使用sum（isdefault）= 0，尽管它仍然可以正常工作。我假设默认情况永远不会消极

SELECT LastName, FirstName, Title 
FROM <yourtable>
GROUP BY LastName, FirstName, Title
HAVING sum(isdefault+0) = 0

这将返回

LastName   FirstName  Title
Leverling  Janet      Sales Representative

Answer 3

你觉得怎么样？这将为您提供您正在寻找的结果。

SELECT e1.*
FROM Employees e1
    left join (SELECT distinct LastName, FirstName FROM Employees t WHERE isdefault = 1 ) exclude
        ON e1.FirstName = exclude.FirstName
        AND e1.LastName = exclude.LastName
WHERE (Exclude.FirstName IS NULL AND Exclude.LastName IS NULL)

我假设FirstName + LastName是你的密钥。如果你有一个id，你应该替换它..

在SQL Server中对一些字段= 0的重复记录进行分组

3 个答案: