mysql - 仅从员工组中获取第一条记录

Question

我有以下数据：

emp_no  emp_name    login   level   HOD_NAME    Assigend_IP LoggedIn_IP Attendece_Location  Shift_Timing
E31446  Amit Singh  09:39   Direct  P00212  172.29.23.53    172.29.23.53    CSO-Ackruti Star-6F 09:30-18:30
E31446  Amit Singh  09:39   Direct  P00212  172.29.23.53    172.29.23.53    CSO-Ackruti Star-6F 09:30-18:30
E39787  Anita Haridas Shenoy    09:41   Indirect    E31446  172.29.24.38    172.29.23.55    CSO-Ackruti Star-6F 09:30-18:30
E39787  Anita Haridas Shenoy    09:41   Indirect    E31446  172.29.24.38    172.29.24.38    CSO-Ackruti Star-6F 09:30-18:30
E39787  Anita Haridas Shenoy    09:41   Indirect    E31446  172.29.24.38    172.29.23.55    CSO-Ackruti Star-6F 09:30-18:30
E39787  Anita Haridas Shenoy    09:41   Indirect    E31446  172.29.24.38    172.29.24.38    CSO-Ackruti Star-6F 09:30-18:30
E37731  Ramesh Shukla   09:40   Indirect    E31446  172.29.23.43    172.29.23.43    CSO-Ackruti Star-6F 09:30-18:30
E37731  Ramesh Shukla   09:40   Indirect    E31446  172.29.23.43    172.29.23.55    CSO-Ackruti Star-6F 09:30-18:30
E33995  Rakesh Sharma   08:21   Direct  P00212  172.29.23.17    172.29.23.17    CSO-Ackruti Star-6F 09:30-18:30
E43130  Lubna Shaikh    09:37   Indirect    E33995  172.29.23.54    172.29.23.54    CSO-Ackruti Star-6F 09:30-18:30
E43130  Lubna Shaikh    09:37   Indirect    E33995  172.29.23.54    172.29.23.58    CSO-Ackruti Star-6F 09:30-18:30
E43130  Lubna Shaikh    09:37   Indirect    E33995  172.29.23.54    172.29.23.54    CSO-Ackruti Star-6F 09:30-18:30
E43130  Lubna Shaikh    09:37   Indirect    E33995  172.29.23.54    172.29.23.58    CSO-Ackruti Star-6F 09:30-18:30
E43455  Manish Shukla       Indirect    E33995  172.29.23.45    172.29.23.45    CSO-Ackruti Star-6F 09:30-18:30
E44920  Shweta Salve    09:18   Indirect    E33995  172.29.23.55    172.29.23.55    CSO-Ackruti Star-6F 09:30-18:30

现在我想以这种方式过滤这些数据，以便我可以得到如下输出的数据：

emp_no  emp_name    login   level   HOD_NAME    Assigend_IP LoggedIn_IP Attendece_Location  Shift_Timing
E31446  Amit Singh  9:39    Direct  P00212  172.29.23.53    172.29.23.53    CSO-Ackruti Star-6F 09:30-18:30
E39787  Anita Haridas Shenoy    9:41    Indirect    E31446  172.29.24.38    172.29.23.55    CSO-Ackruti Star-6F 09:30-18:30
E37731  Ramesh Shukla   9:40    Indirect    E31446  172.29.23.43    172.29.23.43    CSO-Ackruti Star-6F 09:30-18:30
E33995  Rakesh Sharma   8:21    Direct  P00212  172.29.23.17    172.29.23.17    CSO-Ackruti Star-6F 09:30-18:30
E43130  Lubna Shaikh    9:37    Indirect    E33995  172.29.23.54    172.29.23.54    CSO-Ackruti Star-6F 09:30-18:30
E43455  Manish Shukla       Indirect    E33995  172.29.23.45    172.29.23.45    CSO-Ackruti Star-6F 09:30-18:30
E44920  Shweta Salve    9:18    Indirect    E33995  172.29.23.55    172.29.23.55    CSO-Ackruti Star-6F 09:30-18:30

输出应该只包含每个员工的第一条记录。我如何为此编写查询？

score 2 · Accepted Answer

select 
emp_no,emp_name,login,level,
HOD_NAME,Assigend_IP,min(LoggedIn_IP),
Attendece_Location,Shift_Timing
from table_name
group by 
emp_no,emp_name,login,level,
HOD_NAME,Assigend_IP,
Attendece_Location,Shift_Timing

score 1 · Accepted Answer

以下是使用ROW_NUMBER函数的完整工作示例。关键部分是以下行：

ROW_NUMBER() OVER ( PARTITION BY [emp_no] ORDER BY [emp_no] )

这意味着将为每一行生成“ID”号，按 [emp_no] 列对行进行分组。如果您需要其他排序条件，您可以使用任何一列。

这是整个代码：

SET NOCOUNT ON
GO

    DECLARE @DataSource TABLE
    (
         [emp_no] VARCHAR(6)
        ,[emp_name] NVARCHAR(24)
        ,[login] VARCHAR(6)
        ,[level] NVARCHAR(25)
        ,[HOD_NAME] NVARCHAR(24)
        ,[Assigend_IP ] NVARCHAR(64)
        ,[LoggedIn_IP ] NVARCHAR(64)
        ,[Attendece_Location] NVARCHAR(64)
        ,[Shift_Timing] NVARCHAR(64)
    ) 

    INSERT INTO @DataSource
    VALUES   ('E31446','Amit Singh','09:39',' Direct','P00212','172.29.23.53','172.29.23.53','CSO-Ackruti Star-6F','09:30-18:30')
            ,('E31446','Amit Singh','09:39',' Direct','P00212','172.29.23.53','172.29.23.53','CSO-Ackruti Star-6F','09:30-18:30')
            ,('E39787','Anita Haridas Shenoy','09:41',' Indirect','E31446','172.29.24.38','172.29.23.55','CSO-Ackruti Star-6F','09:30-18:30')
            ,('E39787','Anita Haridas Shenoy','09:41',' Indirect','E31446','172.29.24.38','172.29.24.38','CSO-Ackruti Star-6F','09:30-18:30')
            ,('E39787','Anita Haridas Shenoy','09:41',' Indirect','E31446','172.29.24.38','172.29.23.55','CSO-Ackruti Star-6F','09:30-18:30')
            ,('E39787','Anita Haridas Shenoy','09:41',' Indirect','E31446','172.29.24.38','172.29.24.38','CSO-Ackruti Star-6F','09:30-18:30')
            ,('E37731','Ramesh Shukla',' 09:40',' Indirect','E31446','172.29.23.43','172.29.23.43','CSO-Ackruti Star-6F','09:30-18:30')
            ,('E37731','Ramesh Shukla',' 09:40',' Indirect','E31446','172.29.23.43','172.29.23.55','CSO-Ackruti Star-6F','09:30-18:30')
            ,('E33995','Rakesh Sharma',' 08:21',' Direct','P00212','172.29.23.17','172.29.23.17','CSO-Ackruti Star-6F','09:30-18:30')
            ,('E43130','Lubna Shaikh','09:37',' Indirect','E33995','172.29.23.54','172.29.23.54','CSO-Ackruti Star-6F','09:30-18:30')
            ,('E43130','Lubna Shaikh','09:37',' Indirect','E33995','172.29.23.54','172.29.23.58','CSO-Ackruti Star-6F','09:30-18:30')
            ,('E43130','Lubna Shaikh','09:37',' Indirect','E33995','172.29.23.54','172.29.23.54','CSO-Ackruti Star-6F','09:30-18:30')
            ,('E43130','Lubna Shaikh','09:37',' Indirect','E33995','172.29.23.54','172.29.23.58','CSO-Ackruti Star-6F','09:30-18:30')
            ,('E43455','Manish Shukla','',' Indirect','E33995','172.29.23.45','172.29.23.45','CSO-Ackruti Star-6F','09:30-18:30')
            ,('E44920','Shweta Salve','09:18',' Indirect','E33995','172.29.23.55','172.29.23.55','CSO-Ackruti Star-6F','09:30-18:30')

    ;WITH DataSource AS
    (
        SELECT ROW_NUMBER() OVER ( PARTITION BY [emp_no] ORDER BY [emp_no] ) AS [RecordNumber]
              ,[emp_no] 
              ,[emp_name] 
              ,[login] 
              ,[level] 
              ,[HOD_NAME] 
              ,[Assigend_IP ] 
              ,[LoggedIn_IP ] 
              ,[Attendece_Location] 
              ,[Shift_Timing] 
        FROM @DataSource
    )
    SELECT [emp_no] 
          ,[emp_name] 
          ,[login] 
          ,[level] 
          ,[HOD_NAME] 
          ,[Assigend_IP ] 
          ,[LoggedIn_IP ] 
          ,[Attendece_Location] 
          ,[Shift_Timing] 
    FROM DataSource
    WHERE [RecordNumber] = 1

SET NOCOUNT OFF
GO

这是输出：

在此处输入图像描述

score 0 · Accepted Answer

 SELECT * 
   FROM EmployeeLog LOG
        INNER JOIN
        (
           SELECT emp_name, 
                  MAX(login) AS last_login
            FROM EmployeeLog
                 GROUP BY emp_name
        ) LATEST
           ON LOG.emp_name = LATEST.emp_name
           AND LOG.login = LATEST.last_login

这将为每个员工提供最新的登录记录，这就是我认为你所追求的。

如果您是在最早登录之后，MAX()请将子查询中的更改为MIN().

score 0 · Accepted Answer

这是从重复记录中仅获取一条记录的查询，

 SELECT * ,count(*) as cnt,emp_name FROM `emp`
 group by emp_name

mysql - 仅从员工组中获取第一条记录

4 回答 4

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