1.mysql的連接
默認不能遠程連接mysql數據庫需要給權限的。
grant all on *.* to root@'%' identified by '(yourpassword)';
mysql -uroot -p123456 -h127.0.0.1
2.mysql的版本信息
select version()
status
[root@nginx ~]# mysqladmin version -uroot -p123456
3.修改數據庫密碼
mysqladmin -uroot password 123456 -p
4.新增用戶
grant select on *.* to user1@"%" identified by "123456";
5.如果用戶密碼丟失
將所有mysql的進程殺死
mysqld_safe -user=root --skip-grant-tables &
update mysql.user set password=PASSWORD (‘123456’) where User='root';
flush privileges
6.改mysql的表名
alter table user rename users
7.查看錶的結構
desc users
8、修改結構
#表position增加列test
alter table position add(test char(10));
#表position修改列test
alter table position modify test char(20) not null;
#表position修改列test默認值
alter table position alter test set default 'system';
#表position去掉test默認值
alter table position alter test drop default;
#表position去掉列test
alter table position drop column test;
#表depart_pos刪除主鍵
alter table depart_pos drop primary key;
#表depart_pos增加主鍵
alter table depart_pos add primary key PK_depart_pos (department_id,position_id);