Q009:升級過程中提示(1062) Duplicate entry '***' for key 'username'ALTER TABLE common_member CONVERT TO CHARACTER SET utf8mb4COLLATE utf8mb4_unicode_ci;(common_member也可能是common_member_archive)
A009:首先,這一般是UC升級1.7.0后UC里應用通信失敗導致改名通知未被全部執行就進行了X程序升級引起的,解決方法有多種。
select uid from pre_ucenter_members where username in (select username from pre_ucenter_members group by convert(username using utf8mb4) collate utf8mb4_unicode_ci having count(1) > 1)