rainnguy的专栏

[color=blue]1: mysql : 创建新的用户后，给用户赋予新的权利： 1. grant all privileges on *.* to 'penny'@'%' identified by '1' with grant option; 2. 将数据库中数据导出放在指定目录中（在bin下执行，黑窗口要进入到bin下） mysqldump -u pe...

[color=blue][color=blue][color=blue]1. left join 用法： Select distinct a.name, a.age", a.id", date_format(a.date, '%Y-%m-%d'), b.name, b.age, c.name, c.id, c.age from student_one a left join ...