比较第一与第二个字符串,是否有连续的5个字符相同.sql

这是CSDN SQL Server 版主邹建的SQL笔记

--比较第一与第二个字符串,是否有连续的5个字符相同,如果有,返回1,否则返回0

if exists (select * from dbo.sysobjects where id = object_id(N'[dbo].[f_compstr]') and xtype in (N'FN', N'IF', N'TF'))
drop function [dbo].[f_compstr]
GO

if exists (select * from dbo.sysobjects where id = object_id(N'[序数表]') and OBJECTPROPERTY(id, N'IsUserTable') = 1)
drop table [序数表]
GO

--为提高效率,最好创建一个固定的序数表
select top 1600 id=identity(int,1,1) into 序数表 from sysobjects a,sysobjects b

go
create function f_compstr(
@str1 varchar(8000),
@str2 varchar(8000)
) returns bit
as
begin
	declare @re bit
	/*--如果使用动态序数,效率极低.
	declare @tb table(id int identity(1,1),a int)
	insert into @tb(a) select top 1600 null from sysobjects a,sysobjects b
	--*/
	
	if len(@str1)>len(@str2) set @re=case when exists(
		select 1
		from (select name=@str2)a,序数表 b  --使用动态序数,改为: ,@tb b
		where b.id<=len(@str2)-4 and @str1 like '%'+substring(name,b.id,5)+'%'
		) then 1 else 0 end
	else set @re=case when exists(
		select 1
		from (select name=@str1)a,序数表 b  --使用动态序数,改为: ,@tb b
		where b.id<=len(@str1)-4 and @str2 like '%'+substring(name,b.id,5)+'%'
		) then 1 else 0 end
	return(@re)
end
go

--调用示例
select dbo.f_compstr('浦东：田园小区148号405室','浦：田园小区148幢405室')
go

--使用例子,查询不重复的记录,重复的,只显示第一条:
declare @t table(id int identity(1,1),address varchar(1000))
insert into @t
select '浦东：田园小区148号405室'
union all select '浦：田园小区148幢405室'
union all select '浦：田园小区148幢405室'
union all select '浦：田园小区148幢405室'
union all select 'abcdefghijklmn'
union all select 'abcdefg'
union all select 'abcdefghijklmn'
union all select 'abcdefg'
union all select '123456768898'
union all select '123345'

select * from @t a
where id=(select min(id) from @t where dbo.f_compstr(a.address,address)=1)

/*--测试结果

id          address                     
----------- ----------------------------
1           浦东：田园小区148号405室
5           abcdefghijklmn
9           123456768898
10          123345
--*/