删除记录的前缀

--建表

SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
IF NOT EXISTS (SELECT * FROM sys.objects WHERE object_id = OBJECT_ID(N'[dbo].[Table_1]') AND type in (N'U'))
BEGIN
CREATE TABLE [dbo].[Table_1](
	[ID] [int] IDENTITY(1,1) NOT NULL,
	[UserName] [nvarchar](50) NULL,
 CONSTRAINT [PK_Table_1] PRIMARY KEY CLUSTERED 
(
	[ID] ASC
)WITH (IGNORE_DUP_KEY = OFF) ON [PRIMARY]
) ON [PRIMARY]
END
go

--插入测试数据

insert into [Table_1]([UserName])values('asd_1');
insert into [Table_1]([UserName])values('asd_2');
insert into [Table_1]([UserName])values('asd_3');
insert into [Table_1]([UserName])values('a阿斯顿sd_4');
insert into [Table_1]([UserName])values('asd_5');
insert into [Table_1]([UserName])values('6');
insert into [Table_1]([UserName])values('as阿斯顿飞d_7');
insert into [Table_1]([UserName])values('asd_8');

--查看数据
select * from table_1

--更新每次修改的数据
update table_1 set UserName='asd_1' where id=1;
update table_1 set UserName='asd_2' where id=2;
update table_1 set UserName='asd_3' where id=3;
update table_1 set UserName='a阿斯顿sd_4' where id=4;
update table_1 set UserName='asd_5' where id=5;
update table_1 set UserName='6' where id=6;
update table_1 set UserName='as阿斯顿飞d_7' where id=7;
update table_1 set UserName='asd_8' where id=8;

--采用stuff删除记录的前缀
update table_1 set UserName=stuff(UserName,1,charindex('_',UserName),'')
--采用substring删除记录的前缀
update table_1 set UserName=substring(UserName,charindex('_',UserName)+1,len(UserName));
--采用replace删除记录的前缀
update table_1 set UserName=replace(UserName,substring(UserName,1,charindex('_',UserName)),'');