mssql sqlserver 将字段null(空值)值替换为指定值的三种方法分享

create table test(keyId int identity, info varchar(30))
go
insert into test(info)values(‘a‘),(‘b‘),(null),(‘d‘)
go 
---方法1:使用isnull替换
select keyId,isnull(info,‘替换null值‘) as info from test 
go 
---方法2:使用case when 替换
select keyId,case when info is null then ‘替换null值‘ else info end as info from test 
---方法3:使用coalesce替换相应的值
select keyId , coalesce(info,‘替换null值‘) as info from test 

go 
truncate table test 
drop table test