摘要：修改my.cnf [mysqld] 域中添加skip-grant-tables 重启mysqld服务 systemctl restart mysqld 重新使用空密码登录，直接敲回车 mysql -u root -p 切换数据库，并将密码清空 mysql >use mysql; mysql >upd 阅读全文

摘要：书写顺序：select [查询列表] from [表] [连接类型] join [表2] on [连接条件] where [筛选条件] group by [分组列表] having [分组后的筛选条件] order by [排序列表] limit [偏移, 条目数] 执行顺序：from [表] [连 阅读全文