庸医2048的博客

select * from seeds where replace(wechat_id,' ','666') like '666%'

问题：[SQL] select * from attachments where md5 in (select md5 from attachments_md5 where md5<>'0')[Err] 1267 - Illegal mix of collations (utf8mb4_general_ci,IMPLICIT) and (utf8mb4_unicode_ci...

select * from user_copy where HEX(email) REGEXP '^(..)*(E[4-9])'学习链接

Mysql 这个函数的用法 GROUP_CONCAT 需要配合着分组进行的。就是以一个东西为组区分，合并一个另外一个东西的所有数据。select order_id,GROUP_CONCAT(product_name) as product_name from t_order_product GROUP BY order_id...