mssql在update中用join 用from

select * from  TB_PD_BUG_DATA
left JOIN
dbo.TB_BUG ON dbo.TB_PD_BUG_DATA.PDBD_BUG_ID = dbo.TB_BUG.BUG_ID
left JOIN
dbo.TB_PROCESS ON dbo.TB_BUG.BUG_PRC_ID = dbo.TB_PROCESS.PRC_ID
where prc_name like '%asdf)%' and pdbd_prc_dept_id=0

 ---------------------------------------------------------------------------------
update  TB_PD_BUG_DATA set pdbd_prc_dept_id=37
from TB_PD_BUG_DATA
left JOIN
dbo.TB_BUG ON dbo.TB_PD_BUG_DATA.PDBD_BUG_ID = dbo.TB_BUG.BUG_ID
left JOIN
dbo.TB_PROCESS ON dbo.TB_BUG.BUG_PRC_ID = dbo.TB_PROCESS.PRC_ID
where prc_name like '%asdf%' and pdbd_prc_dept_id=0
------------------
--- update不能同时更新多个表

 

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----将b表的某字段改成与a表的某字段相同的数据。 
create table a
(
 a1 varchar(30),
 a2 varchar(30)
)
go
create table b
(
   b1 varchar(30),
   b3 varchar(30),
   b2 varchar(40)
)
insert into a values('6','66666')
select * from a
select * from b
update b set b.b2=a.a2 from a,b where(a.a1=b.b1)