第二十四课 MySQL常用操作

目录

1. 设置、更改 root 密码

2. 连接 MySQL

3. MySQL 常用命令

4. MySQL 用户管理

5. MySQL 常用语句

6. MySQL 的备份与恢复

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1. 设置、更改 root 密码

1.1 将 mysql 的 bin 目录加入 PATH

[root@LNMP ~]# vim .bash_profile 

# .bash_profile

# Get the aliases and functions
if [ -f ~/.bashrc ]; then
        . ~/.bashrc
fi

# User specific environment and startup programs

PATH=$PATH:$HOME/bin:/usr/local/nginx/sbin:/usr/local/mysql/bin

export PATH



[root@LNMP ~]# source .bash_profile

1.2 测试是否需要密码

[root@LNMP ~]# mysql -uroot -p
Enter password: 
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 2
Server version: 5.6.36 MySQL Community Server (GPL)

Copyright (c) 2000, 2017, Oracle and/or its affiliates. All rights reserved.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql> 

1.3 设置密码

[root@LNMP ~]# mysqladmin -uroot password '123123';
Warning: Using a password on the command line interface can be insecure.


[root@LNMP ~]# mysql -uroot -p123123
Warning: Using a password on the command line interface can be insecure.
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 4
Server version: 5.6.36 MySQL Community Server (GPL)

Copyright (c) 2000, 2017, Oracle and/or its affiliates. All rights reserved.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql> 

1.4 改密

[root@LNMP ~]# mysqladmin -uroot -p'123123' password '456456'
Warning: Using a password on the command line interface can be insecure.
[root@LNMP ~]# mysql -uroot -p456456
Warning: Using a password on the command line interface can be insecure.
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 6
Server version: 5.6.36 MySQL Community Server (GPL)

Copyright (c) 2000, 2017, Oracle and/or its affiliates. All rights reserved.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql> 

1.5 当忘记root密码

1.5.1 修改 my.conf，加入 skip-grant

[root@LNMP ~]# vim /etc/my.cnf

# For advice on how to change settings please see
# http://dev.mysql.com/doc/refman/5.6/en/server-configuration-defaults.html
# *** DO NOT EDIT THIS FILE. It's a template which will be copied to the
# *** default location during install, and will be replaced if you
# *** upgrade to a newer version of MySQL.

[mysqld]
skip-grant    # 加入该行

basedir = /usr/local/mysql
datadir = /data/mysql
port = 3306

socket = /tmp/mysql.sock



sql_mode=NO_ENGINE_SUBSTITUTION,STRICT_TRANS_TABLES

1.5.2 重启 mysqld

[root@LNMP ~]# /etc/init.d/mysqld restart
Shutting down MySQL.. SUCCESS! 
Starting MySQL. SUCCESS! 

1.5.3 免密登录

[root@LNMP ~]# mysql -uroot
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 1
Server version: 5.6.36 MySQL Community Server (GPL)

Copyright (c) 2000, 2017, Oracle and/or its affiliates. All rights reserved.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql>                      # 成功登录

1.5.4 用 password 函数，修改数据库中存储的 root 密码

mysql> 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
mysql> update user set password=password('123123') where user='root';
Query OK, 4 rows affected (0.02 sec)
Rows matched: 4  Changed: 4  Warnings: 0

1.5.5 别忘了将 my.conf 中的 skip-grant 去除，并重启

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2. 连接 MySQL

2.1 普通连接

mysql -uroot -p123123

2.2 远程连接

mysql -uroot -p123123 -h192.168.1.1 -P3306

2.3 本地 socket 连接

mysql -uroot -p123123 -S/tmp/mysql.sock

2.4 直接在 Linux 命令行中执行 SQL 语句

mysql -uroot -p123123 -e "show databases"

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3. MySQL 常用命令

• 查库
  show databases;
• 切库
  use mysql;
• 查表
  show tables;
• 查字段
  desc tb_name;
• 查建表语句
  show create table tb_name\G; ## \G 代表竖排显示
• 查当前用户
  select user();
• 查当前数据库
  select databsase();
• 建库
  create database db1;
• 建表
  use db1; create table t1(idint(4),namechar(40));
use db1; create table t1(idint(4),namechar(40)) ENGINE=InnoDB DEFAULT CHARSET=utf8;
• 查当前 mysql 版本
  select version();
• 查数据库状态
  show status;
• 查各种参数
  show variables; show variables like 'max_connect%';
• 改参数
  set global max_connect_errors=1000; # 仅为临时修改，若要永久修改需配置 my.conf 文件
• 查队列
  show processlist;
show full processlist;

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4. MySQL 用户管理

• grant all on *.* to 'user1' identified by 'passwd';
• grant SELECT,UPDATE,INSERT on db1.* to 'user2'@'192.168.133.1' identified by 'passwd';
• grant all on db1.* to 'user3'@'%' identified by 'passwd';
• show grants;
• show grants for [email protected];

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5. MySQL 常用语句

select count(*) from mysql.user;
select * from mysql.db;
select db from mysql.db;
select db,user from mysql.db;
select * from mysql.db where host like ‘192.168.%’;
insert into db1.t1 values (1, ‘abc’);
update db1.t1 set name=’aaa’ where id=1;
truncate table db1.t1;
drop table db1.t1;
drop database db1;

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6. MySQL 的备份与恢复

• 备份库
  mysqldump -uroot -p123456 mysql > /tmp/mysql.sql
• 恢复库
  mysql -uroot -p123456 mysql < /tmp/mysql.sql
• 备份表
  mysqldump -uroot -p123456 mysql user > /tmp/user.sql
• 恢复表
  mysql -uroot -p123456 mysql < /tmp/user.sql
• 备份所有库
  mysqldump -uroot -p -A >/tmp/123.sql
• 只备份表结构
  mysqldump -uroot -p123456 -d mysql > /tmp/mysql.sql