declare @cl nvarchar(100) set @cl=N'Sjöblom' update tb set cl=@cl where id=3
create table tb(id int,cl nvarchar(100)) insert into tb select 3,null union all select 4,null go --如何把这句sql 改写为下面的那种方式? update tb set cl=N'Sjöblom' where id=3 select * from tb /* id cl ----------- ---------------------------------------------------------------------------------------------------- 3 Sjöblom 4 NULL(2 行受影响) */ --改写为这种方式 declare @cl nvarchar(100) set @cl=N'Sjöblom' update tb set cl=@cl where id=4 select * from tb /* id cl ----------- ---------------------------------------------------------------------------------------------------- 3 Sjöblom 4 Sjöblom(2 行受影响) */ go drop table tb
set @cl=N'Sjöblom'
update tb set cl=@cl where id=3
insert into tb select 3,null union all select 4,null
go
--如何把这句sql 改写为下面的那种方式?
update tb set cl=N'Sjöblom' where id=3
select * from tb
/*
id cl
----------- ----------------------------------------------------------------------------------------------------
3 Sjöblom
4 NULL(2 行受影响)
*/
--改写为这种方式
declare @cl nvarchar(100)
set @cl=N'Sjöblom'
update tb set cl=@cl where id=4
select * from tb
/*
id cl
----------- ----------------------------------------------------------------------------------------------------
3 Sjöblom
4 Sjöblom(2 行受影响)
*/
go
drop table tb