SQL匹配度查询

SELECT (IF(LOCATE('RK', SJXBSF), 2, 0)+IF(LOCATE('SJ', SJXBSF), 2, 0)) ppd,o.* FROM db_sjx  o WHERE  ( (SJXBSF LIKE '%RK%') 

OR (SJXBSF LIKE '%SJ%')  ) 

ORDER BY ppd desc,LENGTH(SJXBSF) asc limit 0,24