Mysql 使用笔记

长时间连接而导致关闭connection的相关参数

错误: send of 51 bytes failed with errno=104 Connection reset by peer

#my.cnf max_connections = 200 connect_timeout = 50 wait_timeout = 6000

字符串连接：

update c2_fe_user_profile set fullname=CONCAT(ifnull(firstname, ''), lastname);