sql多表联查实例

下面提供四款sql多表关联查询的实例，个个效率不一样。

select * from order_info as a ,ivrlog4ivrdlvinst as b

where

(a.saleorder=b.ext1_skill and b.start_date=@date1 and se_ and b.ext1_skill!='')

and convert(varchar(10),a.instime,112)=@date2 and max(a.instime)

方法二

select * from order_info as a

where a.saleorder=(

select b.ext1_skill from ivrlog4ivrdlvinst as b

where b.start_date=@date1 and se_

and b.ext1_skill!='')

and convert(varchar(10),max(a.instime),112)=@date2

方法三

declare

@date1 varchar(20),

@date2 varchar(20)

set @date1='20100812'

set @date2='2010-08-12'

select * from order_info as a

where a.saleorder=

(select b.ext1_skill from ivrlog4ivrdlvinst as b where b.start_date=@date1 and se_ and b.ext1_skill!='')

and convert(varchar(10),a.instime,112)=@date2

and max(a.instime)

方法四

select b.caller, b.start_date, b.start_time, b.ext1_skill,

c.deliveryno, c.destroyresult, c.deliverydate, c.deliverytime, c.arrangetime, c.driverphone, c.drivermobile,

a.servicedate, a.servicetime, a.workertel

from order_info as a ,ivrlog4ivrdlvinst as b ,delivery_info as c

where

a.saleorder in (select b.ext1_skill from ivrlog4ivrdlvinst where b.start_date=@date1 and b.se_ and b.ext1_skill!='')

and convert(varchar(10),a.instime,112)=@date2

order by b.start_date desc, b.start_time desc