mysql判断字符串是否存在几种常见方式

SELECT   '貂蝉'  LIKE  '%貂蝉%';

SELECT   FIND_IN_SET('貂蝉','西施,昭君,貂蝉,赵飞燕');

SELECT   LOCATE('西施','西施,昭君,貂蝉,赵飞燕');
SELECT   LOCATE('貂蝉','西施、昭君、貂蝉、赵飞燕');
SELECT   LOCATE('貂蝉','西施昭君貂蝉赵飞燕');

SELECT  LOCATE('貂蝉','西施、昭君、貂蝉、赵飞燕')>0;

SELECT  INSTR('西施、昭君、貂蝉、赵飞燕、西施、','西施');
SELECT  INSTR('西施、昭君、貂蝉、赵飞燕','昭君') > 0;

--  =============================================
--  Author:        <何剑伟>
--  Create date: <2008-03-19>
--  Description:    <获取一个长字符串中某个字符串出现次数>
--  =============================================
 ALTER   FUNCTION   [ dbo ] . [ fun_RepeatCharNum ]
(    
     @CodeString   varchar ( 2000 ),
     @RepeatString   varchar ( 200 )
)
 RETURNS   int  
 AS
 BEGIN  
     DECLARE
         @RepeatStringLen   int ,     -- 检测重复字符的长串
          @TempString   varchar ( 500 )     -- 临时字符串(总比@RepeatString多一个即长度大1)
     
     SET   @RepeatStringLen = LEN ( @RepeatString )
     SET   @TempString = Replicate ( ' | ' , @RepeatStringLen ) + ' | '

     RETURN   LEN ( REPLACE ( @CodeString , @RepeatString , @TempString )) - LEN ( @CodeString )
 END