对单个查询使用带有ORDER BY的UNION子句

我有一个包含此类数据的表。对单个查询使用带有ORDER BY的UNION子句

Id  PId   Device    Status   Type  Created_Date 
===  ===   ======    ======   ====  ============ 
1   2   1     today   High  2012-04-12 08:11:51.583 
2   2   4     today   Medium 2012-04-02 01:39:52.393 
3   3   5     today   Medium 2012-04-02 01:10:02.443 
4   2   6     today   High  2012-04-02 01:05:25.063 
5   2   3     today   High  2012-04-02 01:03:08.360 
6   2   7     today   High  2012-04-02 01:02:57.093 
7   2   2     today   High  2012-04-02 00:22:37.807

现在，我希望设备6和7的记录总是按照创建日期的降序排列在记录集的顶部。和设备类型6和7

的记录后，除了器件6和7顺序按类型和创建日期降序记录所以期望的结果是象下面这样：

Id  PId   Device    Status   Type  Created_Date 
===  ===   ======    ======   ====  ============ 
4   2   6     today   High  2012-04-02 01:05:25.063 
6   2   7     today   High  2012-04-02 01:02:57.093 
1   2   1     today   High  2012-04-12 08:11:51.583 
5   2   3     today   High  2012-04-02 01:03:08.360 
7   2   2     today   High  2012-04-02 00:22:37.807 
2   2   4     today   Medium 2012-04-02 01:39:52.393

我已经使用作为查询如下：

select * from TblAlert where PId=2 and (Device=6 OR Device=7) and (Status='Today' or Status=0) 
UNION 
Select * from TblAlert Where PId=2 and (Device<>6 OR Device<>7)and (Status='Today' or Status=0) 
order by Type,Created_Date desc

但它没有工作，因为它是在整个记录集上应用子句。

有人可以帮我吗？

来源

2012-04-23 Dev

当您使用'UNION'将结果合并成使用两个查询一个表解决了这个问题我自己'ORDER BY'条款并不完全对工作结果。 – Murtaza 2012-04-23 04:50:43

利用表变量作为

DECLARE @Records TABLE 
(
    Id int, 
    PId int, 
    Device int, 
    Status Alert_Type varchar(10), 
    Type Alert_Type varchar(5), 
    Created_Date DateTime 
); 

INSERT @Records 
    SELECT Id, PId, Device, Status,Type,Created_Date FROM 
     TblAlert 
    WHERE 
     PId =2 
     AND Device IN (6,7) 
     AND (Status='Today' or Status=0) 
    ORDER BY 
     Created_Date DESC; 

INSERT @Records 
    SELECT Id, PId, Device, Status,Type,Created_Date FROM 
     TblAlert 
    WHERE 
     PId =2 
     AND Device NOT IN (6,7) 
     AND (Status='Today' or Status=0) 
    ORDER BY 
     Type, Created_Date DESC; 

SELECT * FROM @Records;

来源

2012-05-09 12:39:13 Dev

**这不是如何解决这个问题**你很幸运，数据库按照你插入的顺序返回行。确保您获得一致顺序的唯一方法是使用ORDER BY，而不使用它。你应该看看在ORDER BY中使用CASE，就像@Mikael Eriksson在他的回答中所做的那样。 – 2012-05-09 12:49:47

select * 
from TblAlert 
where PId=2 and ([Status]='Today' or [Status]='0') 
order by case when Device in (6, 7) then 0 else 1 end, 
     case when Device in (6, 7) then [Type] else '' end, 
     Created_Date

来源

2012-04-23 05:17:45

对单个查询使用带有ORDER BY的UNION子句

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