SQL联合查询两个表的数据 - 寒子非

时间:2024-03-09 14:41:48

刚有个项目,需要查询水位数据表中的水位信息,及查询降雨量表中统计时段降雨量的数据,以计算出日降雨量,而且时段是前一天8时到后一天8时总共24个小时。

 

两个子查询:

1、根据当前时间判断统计前天8时到今天8时还是大前天8时到前天8时的时段雨量;

select STCD,SUM(DRP) as drp2 
from Jialiang.dbo.ST_PPTN_R 
where 
STCD=\'1\'and 
TM>case  
when Datename(hour,GetDate())>=8 then CONVERT(varchar(100), GETDATE()-1, 23)+\' 8:00\' else CONVERT(varchar(100), GETDATE()-2, 23)+\' 8:00\' end
and 
TM<case
when Datename(hour,GetDate())>=8 then CONVERT(varchar(100), GETDATE(), 23)+\' 8:00\' else CONVERT(varchar(100), GETDATE()-1, 23)+\' 8:00\'end
GROUP BY STCD

 

2、查询最新的水位数据

select STCD,Z 
from Jialiang.dbo.ST_RIVER_R
where STCD=\'1\' and TM=(select MAX(TM) from Jialiang.dbo.ST_RIVER_R where STCD=\'1\')

 

最后把这两个查询结果根据设备编码联合起来

 

select a.Z,b.drp2 from(select STCD,SUM(DRP) as drp2 
from Jialiang.dbo.ST_PPTN_R 
where 
STCD=\'1\'and 
TM>case  
when Datename(hour,GetDate())>=8 then CONVERT(varchar(100), GETDATE()-1, 23)+\' 8:00\' else CONVERT(varchar(100), GETDATE()-2, 23)+\' 8:00\' end
and 
TM<case
when Datename(hour,GetDate())>=8 then CONVERT(varchar(100), GETDATE(), 23)+\' 8:00\' else CONVERT(varchar(100), GETDATE()-1, 23)+\' 8:00\'end
GROUP BY STCD) as b,
(select STCD,Z 
from Jialiang.dbo.ST_RIVER_R
where STCD=\'1\' and TM=(select MAX(TM) from Jialiang.dbo.ST_RIVER_R where STCD=\'1\')) as a
where a.STCD=b.STCD 

 

本文参考了

SQL获取当前时间的方法:http://www.cnblogs.com/weiqt/articles/2040800.html

DateName()还可以获得到小时、时间、秒、星期几、第几周,分别如下:

Select Datename(hour,GetDate())
Select Datename(minute,GetDate())
Select Datename(second,GetDate())
Select Datename(weekDay,GetDate())
Select Datename(week,GetDate())

 

使用Convert()函数:

select convert(char(10),GetDate(),120) as Date

* 第3个参数就是用来设置日期类型数据的显示样式的,下面介绍几种样式的参数:

100   mm dd yyyy

101   mm/dd/yyyy

102   yyyy.mm.dd

103   dd/mm/yyyy

106   dd mm yyyy

108   hh:mi:ss(时间)

111   yyyy/mm/dd

112   yyyymmdd

120   yyyy-mm-dd hh:mm:ss

23     yyyy-mm-dd

 

1 SELECT CONVERT(varchar(100), GETDATE(), 0) 05 9 2011 9:12AM
2  SELECT CONVERT(varchar(100), GETDATE(), 1) 05/09/11
3 SELECT CONVERT(varchar(100), GETDATE(), 2) 11.05.09
4 SELECT CONVERT(varchar(100), GETDATE(), 3) 09/05/11
5 SELECT CONVERT(varchar(100), GETDATE(), 4) 09.05.11
6 SELECT CONVERT(varchar(100), GETDATE(), 5) 09-05-11
7 SELECT CONVERT(varchar(100), GETDATE(), 6) 09 05 11
8 SELECT CONVERT(varchar(100), GETDATE(), 7) 05 09, 11
9 SELECT CONVERT(varchar(100), GETDATE(), 8) 09:13:14
10 SELECT CONVERT(varchar(100), GETDATE(), 9) 05 9 2011 9:13:14:670AM
11 SELECT CONVERT(varchar(100), GETDATE(), 10) 05-09-11
12 SELECT CONVERT(varchar(100), GETDATE(), 11) 11/05/09
13 SELECT CONVERT(varchar(100), GETDATE(), 12) 110509
14 SELECT CONVERT(varchar(100), GETDATE(), 13) 09 05 2011 09:13:14:670
15 SELECT CONVERT(varchar(100), GETDATE(), 14) 09:13:14:670
16 SELECT CONVERT(varchar(100), GETDATE(), 20) 2011-05-09 09:13:14
17 SELECT CONVERT(varchar(100), GETDATE(), 21) 2011-05-09 09:13:14.670
18 SELECT CONVERT(varchar(100), GETDATE(), 22) 05/09/11 9:15:33 AM
19 SELECT CONVERT(varchar(100), GETDATE(), 23) 2011-05-09
20 SELECT CONVERT(varchar(100), GETDATE(), 24) 09:15:33
21 SELECT CONVERT(varchar(100), GETDATE(), 25) 2011-05-09 09:15:33.140
22 SELECT CONVERT(varchar(100), GETDATE(), 100) 05 9 2011 9:15AM
23 SELECT CONVERT(varchar(100), GETDATE(), 101) 05/09/2011
24 SELECT CONVERT(varchar(100), GETDATE(), 102) 2011.05.09
25 SELECT CONVERT(varchar(100), GETDATE(), 103) 09/05/2011
26 SELECT CONVERT(varchar(100), GETDATE(), 104) 09.05.2011
27 SELECT CONVERT(varchar(100), GETDATE(), 105) 09-05-2011
28 SELECT CONVERT(varchar(100), GETDATE(), 106) 09 05 2011
29 SELECT CONVERT(varchar(100), GETDATE(), 107) 05 09, 2011
30 SELECT CONVERT(varchar(100), GETDATE(), 108) 09:16:38
31 SELECT CONVERT(varchar(100), GETDATE(), 109) 05 9 2011 9:16:38:543AM
32 SELECT CONVERT(varchar(100), GETDATE(), 110) 05-09-2011
33 SELECT CONVERT(varchar(100), GETDATE(), 111) 2011/05/09
34 SELECT CONVERT(varchar(100), GETDATE(), 112) 20110509
35 SELECT CONVERT(varchar(100), GETDATE(), 113) 09 05 2011 09:17:19:857
36 SELECT CONVERT(varchar(100), GETDATE(), 114) 09:17:19:857
37 SELECT CONVERT(varchar(100), GETDATE(), 120) 2011-05-09 09:17:19
38 SELECT CONVERT(varchar(100), GETDATE(), 121) 2011-05-09 09:17:19.857
39 SELECT CONVERT(varchar(100), GETDATE(), 126) 2011-05-09T09:17:19.857
40 SELECT CONVERT(varchar(100), GETDATE(), 130) 6 ????? ??????? 1432 9:17:19:857AM
41 SELECT CONVERT(varchar(100), GETDATE(), 131) 6/06/1432 9:17:19:857AM

 

SQL case when.. else..end 用法:

WHERE  
WATRDJ>= case when P05_TRDJ_FM is not null then V_TRDJ_FM else WATRDJ end and
WATRDJ<= case when P05_TRDJ_TO is not null then V_TRDJ_TO else WATRDJ end

 

SQL联合查询两个表方法:

同一实例下的数据库表是可以直接引用的,只要加上数据库名就可以了
select  a.* from A.dbo.AA as a,B.dbo.AA  as b where a.col1 = b.col1 and a.col2 <> b.col2

 

posted on 2016-12-09 10:46  寒子非  阅读(11264)  评论(2编辑  收藏  举报