mysql中如何判断当前是字符 mysql判断字段中有无汉字

SELECT 
  * 
FROM
  t_ad t 
WHERE t.`userid` = 974 
  AND LENGTH(
    REPLACE(REPLACE(t.`title`, '-', ''), '+', '')
  ) = 3 * CHAR_LENGTH(
    REPLACE(REPLACE(t.`title`, '-', ''), '+', '')
  ) 
  AND t.`deleteflag` = 1 ;