通过以下命令来检查 MySQL 服务器是否启动
ps -ef | grep mysql
例如在我的苹果电脑上运行如下
[root@ddkk.com ~]# ps -ef | grep mysql
mysql 1520 1 0 18:21 ? 00:00:00 /bin/sh /usr/bin/mysqld_safe --basedir=/usr
mysql 1682 1520 0 18:21 ? 00:00:00 /usr/libexec/mysqld --basedir=/usr --datadir=/var/lib/mysql --plugin-dir=/usr/lib64/mysql/plugin --log-error=/var/log/mariadb/mariadb.log --pid-file=/var/run/mariadb/mariadb.pid --socket=/var/lib/mysql/mysql.sock
root 1774 1744 0 18:29 pts/0 00:00:00 grep --color=auto mysql
如果MySql 已经启动，上面的命令会输出 mysql 进程列表 mysqld_safe 和 mysqld
启动 MySQL 命令
如果MySQL 未启动，使用以下命令来启动 MySQL 服务器
[root@ddkk.com ~]# mysqld_safe &
关闭 MySQL 命令
如果想关闭目前运行的 MySQL 服务器, 可以执行以下命令
[root@ddkk.com ~]# mysqladmin -u root -p shutdown
Enter password: ******
MySQL 添加用户
MySQL 服务器默认已经添加了 root 用户
如果需要添加 MySQL 用户，我们只需要在数据库 mysql 中的表 user 中插入新用户即可
下面的SQL 语句可以添加一个新的用户
用户名为 demo 密码为 demo123 并授权用户可进行 SELECT,INSERT,UPDATE 操作权限
INSERT INTO mysql.user (host, user, password, select_priv, insert_priv, update_priv) VALUES ('localhost', 'demo', PASSWORD('demo123'), 'Y', 'Y', 'Y');
然后刷新权限
FLUSH PRIVILEGES;
你可以按照下面的步骤尝试一下
[root@ddkk.com ~]# mysql -uroot -p
Enter password:
Welcome to the MariaDB monitor. Commands end with ; or \g.
Your MariaDB connection id is 6
Server version: 5.5.56-MariaDB MariaDB Server
Copyright (c) 2000, 2017, Oracle, MariaDB Corporation Ab and others.
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
MariaDB [(none)]> USE mysql;
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A
Database changed
MariaDB [mysql]> INSERT INTO user (host, user, password, select_priv, insert_priv, update_priv) VALUES ('localhost', 'demo', PASSWORD('demo123'), 'Y', 'Y', 'Y');
Query OK, 1 row affected, 4 warnings (0.01 sec)
MariaDB [mysql]> FLUSH PRIVILEGES;
Query OK, 0 rows affected (0.00 sec)
MariaDB [mysql]> SELECT host, user, password FROM user WHERE user = 'demo';
+-----------+------+-------------------------------------------+
| host | user | password |
+-----------+------+-------------------------------------------+
| localhost | demo | *3055544BD641D0814B910C4ACA5799F51B80F460 |
+-----------+------+-------------------------------------------+
1 row in set (0.01 sec)
在添加用户时，请注意使用 MySQL 提供的 PASSWORD() 函数来对密码进行加密
我们在上面的范例中看到用户密码加密后为：
3055544BD641D0814B910C4ACA5799F51B80F460
注意
1、 在MySQL5.7中user表的password已换成了authentication_string；
2、 添加用户后需要执行FLUSHPRIVILEGES语句，这个命令执行后会重新载入授权表如果使用该命令，无法使用新创建的用户来连接MySQL服务器，除非重启MySQL服务器；
用户权限
可以在创建用户时，为用户指定权限，在对应的权限列中，在插入语句中设置为 ‘Y’ 即可
用户权限说明
| 命令标识 | 授权表中对应的列 | 说明 |
|---|---|---|
| CREATE | Create_priv | 创建数据库、表或索引 |
| CREATE TEMPORARY TABLES | Create_tmp_table_priv | 创建临时数据表 |
| CREATE ROUTINE | Create_routine_priv | 创建函数或存储 |
| CREATE VIEW | Create_view_priv | 创建视图 |
| CREATE USER | Create_user_priv | 创建用户 |
| EXECUTE | Execute_priv | 执行函数或存储过程 |
| INDEX | Index_priv | 建立索引 |
| REFERENCES | References_priv | 建立约束 |
| DROP | Drop_priv | 删除表 |
| SELECT | Select_priv | 查询数据 |
| INSERT | Insert_priv | 插入数据 |
| UPDATE | Update_priv | 更新数据 |
| DELETE | Delete_priv | 删除数据 |
| LOCK TABLES | Lock_tables_priv | 锁定表格 |
| SHOW DATABASES | Show_db_priv | 列出数据库 |
| SHOW VIEW | Show_view_priv | 列出视图 |
| USAGE | 只有登录权限， 其它权限都没有 | |
| ALL | 所有权限,除了 WITH GRANT OPTION | |
| ALTER | Alter_priv | 更改数据表 |
| ALTER ROUTINE | Alter_routine_priv | 更改函数或存储过程 |
| PROCESS | Process_priv | 显示连接进程和中断连接进程 |
| FILE | File_priv | 载入文件 |
| RELOAD | Reload_priv | 可以用 FLUSH |
| REPLICATION CLIENT | Repl_client_priv | 可以检查 Masters 和 Slaves |
| REPLICATION SLAVE | Repl_slave_priv | 在 Slave 里的特殊权限 |
| SHUTDOWN | Shutdown_priv | 关闭 MySQL |
| WITH GRANT OPTION | Grant_priv | 可以将自己拥有的权限赋给其它用户 |
| SUPER | Super_priv | 执行 kill 线程，change master、purge master logs、set global等命令的权限 |
| create tablespace | Create_tablespace_priv | 创建表空间 |
| Event | Event_priv | 确定用户能否创建、修改和删除事件 |
| Trigger | Trigger_priv | 确定用户能否创建和删除触发器 |
GRANT 命令添加用户
下面的SQL 语句会给指定数据库 test 添加用户 souyunku1 ，密码为 souyunku123xyz
GRANT SELECT,INSERT,UPDATE,DELETE,CREATE,DROP ON test.* TO 'souyunku1'@'localhost' IDENTIFIED BY 'souyunku123xyz';
操作演示
[root@ddkk.com ~]# mysql -uroot -p
Enter password:
Welcome to the MariaDB monitor. Commands end with ; or \g.
Your MariaDB connection id is 8
Server version: 5.5.56-MariaDB MariaDB Server
Copyright (c) 2000, 2017, Oracle, MariaDB Corporation Ab and others.
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
MariaDB [(none)]> USE mysql;
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A
Database changed
MariaDB [mysql]> GRANT SELECT,INSERT,UPDATE,DELETE,CREATE,DROP ON test.* TO 'souyunku1'@'localhost' IDENTIFIED BY 'souyunku123xyz';
Query OK, 0 rows affected (0.00 sec)
MariaDB [mysql]> FLUSH PRIVILEGES;
Query OK, 0 rows affected (0.00 sec)
MariaDB [mysql]> SELECT host, user, password FROM user;
+-----------------------+-------+-------------------------------------------+
| host | user | password |
+-----------------------+-------+-------------------------------------------+
| localhost | root | |
| localhost.localdomain | root | |
| 127.0.0.1 | root | |
| ::1 | root | |
| localhost | | |
| localhost.localdomain | | |
| localhost | demo | *3055544BD641D0814B910C4ACA5799F51B80F460 |
| localhost | souyunku1 | *302D386BA9E00875ADDF9ED0AD447B19FAE2FEDB |
+-----------------------+-------+-------------------------------------------+
8 rows in set (0.00 sec)
MariaDB [mysql]>
/etc/my.cnf 配置文件
一般情况下，我们不需要修改该配置文件，该文件默认配置如下：
[root@ddkk.com ~]# cat /etc/my.cnf
显示内容如下
[mysqld]
datadir=/var/lib/mysql
socket=/var/lib/mysql/mysql.sock
# Disabling symbolic-links is recommended to prevent assorted security risks
symbolic-links=0
# Settings user and group are ignored when systemd is used.
# If you need to run mysqld under a different user or group,
# customize your systemd unit file for mariadb according to the
# instructions in http://fedoraproject.org/wiki/Systemd
[mysqld_safe]
log-error=/var/log/mariadb/mariadb.log
pid-file=/var/run/mariadb/mariadb.pid
# include all files from the config directory
!includedir /etc/my.cnf.d
在配置文件中，我们可以指定不同的错误日志文件存放的目录，但一般不需要改动这些配置