查询的时候区分大小写

UPDATE  problem SET PROBLEM_TYPE=0 WHERE  id IN 

(

 SELECT a.id FROM 

 (

  SELECT id FROM problem  WHERE  LENGTH(ANSWRE)=1    AND  (BINARY   ANSWRE  LIKE '%A' OR   BINARY ANSWRE  LIKE '%B'  OR  BINARY ANSWRE  LIKE '%C'  OR  BINARY ANSWRE  LIKE '%D') 

  AND  PROBLEM_TYPE!=0

  ) a

 )