declare @text varchar(1000)declare @str varchar(10)set @text = 'ABCBDBE'set @str = 'B'select len(@text) - len(replace(@text,@str,''))

--方法1declare @text varchar(1000)declare @str varchar(10)set @text = 'ABBBCBBBDBBBE'set @str = 'BBB'select (len(@text) - len(replace(@text,@str,'')))/len(@str)--方法2declare @text varchar(1000)declare @str varchar(10)set @text = 'ABBBCBBBDBBBE'set @str = 'BBB'select len(replace(@text,@str,@str+'_')) - len(@text)

CHARINDEX ( expressionToFind , expressionToSearch [ , start_location ] )

if object_id('NthChar','FN') is not null  drop function NthcharGOcreate function NthChar(@source_string as nvarchar(4000), @sub_string  as nvarchar(1024),@nth      as int) returns int as begin   declare @postion int   declare @count  int   set @postion = CHARINDEX(@sub_string, @source_string)   set @count = 0   while @postion > 0   begin     set @count = @count + 1     if @count = @nth     begin       break     end    set @postion = CHARINDEX(@sub_string, @source_string, @postion + 1)   End   return @postion end GO--select dbo.NthChar('abcabc','abc',2)--4

if object_id('tempdb..#T') is not null  drop table #Tcreate table #T(source_string nvarchar(4000))insert into #T values (N'我們我們')insert into #T values (N'我我哦我')declare @sub_string nvarchar(1024)declare @nth    intset @sub_string = N'我們'set @nth = 2;with T(source_string, starts, pos, nth) as (  select source_string, 1, charindex(@sub_string, source_string), 1 from #t  union all  select source_string, pos + 1, charindex(@sub_string, source_string, pos + 1), nth+1 from T  where pos > 0)select   source_string, pos, nthfrom Twhere pos <> 0 and nth = @nthorder by source_string, starts--source_string  pos  nth--我們我們  3  2

--numbers/tally tableIF EXISTS (select * from dbo.sysobjects where id = object_id(N'[dbo].[Numbers]') and OBJECTPROPERTY(id, N'IsUserTable') = 1)  DROP TABLE dbo.Numbers--===== Create and populate the Tally table on the fly SELECT TOP 1000000     IDENTITY(int,1,1) AS number  INTO dbo.Numbers  FROM master.dbo.syscolumns sc1,    master.dbo.syscolumns sc2--===== Add a Primary Key to maximize performance ALTER TABLE dbo.Numbers    ADD CONSTRAINT PK_numbers_number PRIMARY KEY CLUSTERED (number)--===== Allow the general public to use it GRANT SELECT ON dbo.Numbers TO PUBLIC--以上數(shù)字表創(chuàng)建一次即可，不需要每次都重復(fù)創(chuàng)建DECLARE @source_string  nvarchar(4000),     @sub_string    nvarchar(1024),     @nth       intSET @source_string = 'abcabcvvvvabc'SET @sub_string = 'abc'SET @nth = 2 ;WITH T AS(      SELECT ROW_NUMBER() OVER(ORDER BY number) AS nth,    number AS [Position In String] FROM dbo.Numbers n  WHERE n.number <= LEN(@source_string)    AND CHARINDEX(@sub_string, @source_string, n.number)-number = 0  ----OR  --AND SUBSTRING(@source_string,number,LEN(@sub_string)) = @sub_string) SELECT * FROM T WHERE nth = @nth

declare @T table(source_string nvarchar(4000))insert into @T values('abcabc'),('abcabcvvvvabc')declare @sub_string nvarchar(1024)set @sub_string = 'abc'select source_string,    p1.pos as no1,    p2.pos as no2,    p3.pos as no3from @Tcross apply (select (charindex(@sub_string, source_string))) as P1(Pos)cross apply (select (charindex(@sub_string, source_string, P1.Pos+1))) as P2(Pos)cross apply (select (charindex(@sub_string, source_string, P2.Pos+1))) as P3(Pos)

--FINDSTRING in SQL Server 2005 SSISFINDSTRING([yourColumn], "|", 2),--TOKEN in SQL Server 2012 SSISTOKEN(Col1,"|",3)

--把兩個連續(xù)空格替換成一個空格，然后循環(huán)，直到charindex檢查不到兩個連續(xù)空格declare @str varchar(100)set @str='abc    abc   kljlk   kljkl'while(charindex(' ',@str)>0)begin  select @str=replace(@str,' ',' ')endselect @str

Oracle 10 gREGEXP_LIKEREGEXP_REPLACEREGEXP_INSTRREGEXP_SUBSTROracle 11g (新增)REGEXP_COUNT

select length(regexp_replace('123-345-566', '[^-]', '')) from dual;select REGEXP_COUNT('123-345-566', '-') from dual; --Oracle 11g 

instr('source_string','sub_string' [,n][,m])

select instr('abcdefghijkabc','abc', 1, 2) position from dual; 

select regexp_replace(trim('agc f  f '),'/s+',' ') from dual; 

--是否為有效IPWITH IPAS(SELECT '10.20.30.40' ip_address FROM dual UNION ALLSELECT 'a.b.c.d' ip_address FROM dual UNION ALLSELECT '256.123.0.254' ip_address FROM dual UNION ALLSELECT '255.255.255.255' ip_address FROM dual)SELECT *FROM IPWHERE REGEXP_LIKE(ip_address, '^(([0-9]{1}|[0-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])/.){3}([0-9]{1}|[0-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])$');--是否為有效身份證/手機(jī)號，暫未舉例

--1. 開啟 CLR EXEC sp_configure 'show advanced options' , '1'GORECONFIGUREGOEXEC sp_configure 'clr enabled' , '1'GORECONFIGUREGOEXEC sp_configure 'show advanced options' , '0';GO

--3. 創(chuàng)建 CLR 函數(shù)CREATE FUNCTION [dbo].[regex_replace](@input [nvarchar](4000), @pattern [nvarchar](4000), @replacement [nvarchar](4000))RETURNS [nvarchar](4000) WITH EXECUTE AS CALLER, RETURNS NULL ON NULL INPUTAS EXTERNAL NAME [RegexUtility].[RegexUtility].[RegexReplaceDefault]GO--4. 使用regex_replace替換多個空格為一個空格select dbo.regex_replace('agc f  f ','/s+',' ');