centOS Linux下用yum安装mysql(三)
s affected (0.03 sec)
mysql> select user from mysql.user where user='centospub';← 确认centospub用户的存在与否
|+----------+
| user |
+-----------+
| centospub |
+-----------+
1 row in set (0.02 sec)
mysql> exit;
Bye
[root@192 local]# mysql -u centospub -p; ← 用新建立的centospub用户登录MySQL服务器
Enter password: ← 在这里输入密码
mysql>create database test; ← 建立名为test的数据库
mysql> show databases; ← 查看系统已存在的数据库
+--------------------+
| Database |
+--------------------+
| information_schema |
| test |
+--------------------+
2 rows in set (0.01 sec)
mysql> use test ← 连接到数据库
Database changed
mysql> create table test
-> (
-> num int , ← 在数据库中建立表
-> name varchar(50)
-> );
Query OK, 0 rows affected (0.14 sec)
mysql> show tables; ← 查看数据库中已存在的表
+----------------+
| Tables_in_test |
+----------------+
| test |
+----------------+
1 row in set (0.02 sec)
mysql> insert into test values(1,'Hello World!'); ← 插入一个值到表中
Query OK, 1 row affected (0.02 sec)
mysql> select * from test; ← 查看数据库中的表的信息
+------+-------------------+
| num | name |
+------+-------------------+
| 1 | Hello World! |
+------+-------------------+
1 row in set (0.00 sec)
mysql> update test set name='Hello Everyone!'; ← 更新表的信息，赋予新的值
Query OK, 1 row affected (0.14 sec)
Rows matched: 1 Changed: 1 Warnings: 0
mysql> select *from test; ← 查看数据库中的表的信息
+------+-----------------+
| num | name |
+------+-----------------+ ← 确认被更新到新的值
| 1 | Hello Everyone! |
+------+-----------------+
1 row in set (0.01 sec)
mysql> delete from test where num=1; ← 删除表内的值
Query OK, 1 row affected (0.01 sec)
mysql> select * from test; ← 确认删除结果
Empty set (0.01 sec)
mysql> drop table test; ← 删除表
Query OK, 0 rows affected (0.01 sec)
mysql> show tables; ← 查看表信息
Empty set (0.00 sec) ← 确认表已被删除
mysql> drop database test; ← 删除名为test的数据库
Query OK, 0 rows affected (0.01 sec)
mysql> show databases; ← 查看已存在的数据库
Empty set (0.01 sec)
← 确认test数据库已被删除（这里非root用户的关系，看不到名为mysql的数据库）
mysql> exit ← 退出MySQL服务器
Bye
然后，删除测试用过的遗留用户
[root@192 local]# mysql -u root -p;
Enter password:
mysql> revoke all privileges on *.* from centospub@localhost;
← 取消centospub用户对数据库的操作权限
Query OK, 0 rows affected (0.01 sec)
mysql> delete from mysql.user where user='centospub'and host='localhost';
← 删除centospub用户
Query OK, 1 row affected (0.14 sec)
mysql> select user from mysql.user where user='centospub';
← 查找用户centospub，确认已删除与否
Empty set (0.01 sec) ← 确认centospub用户已不存在
mysql> flush privileges; ← 刷新，使以上操作生效
Query OK, 0 rows affected (0.00 sec)
mysql> exit;
Bye
[root@192 local]# /etc/rc.d/init.d/httpd restart ← 重新启动HTTP服务
← 注意：语句后面无需;分号
停止 httpd： [确定]
启动 httpd： [确定]
第四篇：日志位置和网络服务器
一、日志位置
mysql 默认的日志位置，mysql日志文件默认存放位置 /var/log/mysqld.log
[root@192 ~]# cd /var/log
[root@192 log]# pwd
/var