1.SQL---1
ALTER table sp_activity CONVERT TO CHARACTER SET utf8 COLLATE utf8_unicode_ci;
2.SQL---2
ALTER TABLE `zhhtdb`.`sp_usercoupon` COLLATE=utf8_unicode_ci
区别：
SQL1执行之后，生效。
SQL2不会生效。问题还存在。
uncategorized SQLException for SQL []; SQL state [HY000]; error code [1267]; Illegal mix of collations (utf8_general_ci,IMPLICIT) and (utf8_unicode_ci,IMPLICIT) for operation '='; nested exception is java.sql.SQLException: Illegal mix of collations (utf8_general_ci,IMPLICIT) and (utf8_unicode_ci,IMPLICIT) for operation '='