Question

我有一个名为Tbl_TickTock的表：

ID  |   STATUS  |   DAYTIME                 |
----|-----------|---------------------------|
1   |   unknown |   2017-03-30  13:30:30    |
1   |   other   |   2016-02-02  10:10:10    |
1   |   active  |   2015-01-01  00:00:00    |

2   |   unknown |   2017-03-30  13:30:30    |
2   |   other   |   2016-02-02  10:10:10    |
2   |   passive |   2015-01-01  00:00:00    |

3   |   other   |   2017-03-30  13:30:30    |
3   |   active  |   2016-02-02  10:10:10    |
3   |   passive |   2015-01-01  00:00:00    |

4   |   passive |   2017-03-30  13:30:30    |
4   |   other   |   2016-02-02  10:10:10    |
4   |   active  |   2015-01-01  00:00:00    |

5   |   unknown |   2017-03-30  13:30:30    |
5   |   passive |   2016-02-02  10:10:10    |
5   |   active  |   2015-01-01  00:00:00    |

6   |   active  |   2017-03-30  13:30:30    |
6   |   passive |   2016-02-02  10:10:10    |
6   |   active  |   2015-01-01  00:00:00    |

DAYTIME数据类型为datetime

我需要两个不同的recorsets。

第一次查询

选择具有以下条件的所有行：

有一行STATUS = 'passive'
还有另一行（或多行）具有相同的ID STATUS ='active'或
STATUS = 'other'此行比ID的最新行更新 STATUS = 'passive'

因此，

ID = 1：已排除，无'passive'

1   |   unknown |   2017-03-30  13:30:30    |
1   |   other   |   2016-02-02  10:10:10    |
1   |   active  |   2015-01-01  00:00:00    |

ID = 4：已排除，'passive'是最新的

4   |   passive |   2017-03-30  13:30:30    |
4   |   other   |   2016-02-02  10:10:10    |
4   |   active  |   2015-01-01  00:00:00    |

ID = 4：排除，没有'active'或'other'比'passive'更新

5   |   unknown |   2017-03-30  13:30:30    |
5   |   passive |   2016-02-02  10:10:10    |
5   |   active  |   2015-01-01  00:00:00    |

结果必须按ID，DAYTIME DESC

排序

从上面的示例结果应该是：

ID  |   STATUS  |   DAYTIME                 |
----|-----------|---------------------------|
2   |   unknown |   2017-03-30  13:30:30    |
2   |   other   |   2016-02-02  10:10:10    |
2   |   passive |   2015-01-01  00:00:00    |

3   |   other   |   2017-03-30  13:30:30    |
3   |   active  |   2016-02-02  10:10:10    |
3   |   passive |   2015-01-01  00:00:00    |

6   |   active  |   2017-03-30  13:30:30    |
6   |   passive |   2016-02-02  10:10:10    |
6   |   active  |   2015-01-01  00:00:00    |

我知道从哪里开始，但我很失落所以跟随可能是没有希望的：

SELECT z1.* 
FROM Tbl_TickTock z1  
INNER JOIN 
    (SELECT MAX(daytime) as MAXdaytime )
    FROM Tbl_TickTock) z2
ON z1.ID = z2.ID
AND ( here we put conditions? : 
        active is newer than passive OR 
        other  is newer than passive  )

第一次查询结束

第二次查询

与FIRST类似，但每个ID只返回一行。

必须填写与FIRST查询相同的条件：

有一行STATUS = 'passive'
还有另一行（或多行）具有相同的ID STATUS ='active'或
STATUS = 'other'此行比ID的最新行更新 STATUS = 'passive'

必须按照以下顺序选择ID行

如果ID有一行：STATUS = 'active'，请选择ID的最新行其中STATUS = 'passive'
否则请选择ID最新的STATUS = 'other'行

来自FIRST查询条件的结果：

ID  |   STATUS  |   DAYTIME                 |
----|-----------|---------------------------|
2   |   unknown |   2017-03-30  13:30:30    |
2   |   other   |   2016-02-02  10:10:10    |   <--- Row to be returned
2   |   passive |   2015-01-01  00:00:00    |

3   |   other   |   2017-03-30  13:30:30    |
3   |   active  |   2016-02-02  10:10:10    |   <--- Row to be returned
3   |   passive |   2015-01-01  00:00:00    |

6   |   active  |   2017-03-30  13:30:30    |   <--- Row to be returned
6   |   passive |   2016-02-02  10:10:10    |
6   |   active  |   2015-01-01  00:00:00    |

结果必须按ID，DAYTIME DESC

从上面的示例结果应该是：

ID  |   STATUS  |   DAYTIME                 |
----|-----------|---------------------------|
2   |   other   |   2016-02-02  10:10:10    |

3   |   active  |   2016-02-02  10:10:10    |

6   |   active  |   2017-03-30  13:30:30    |

第二次查询结束

任何帮助都非常感谢！

SQL Server。按最新列值选择行

0 个答案: