2018-07-11
設置更改root密碼目錄概要
/usr/local/mysql/bin/mysql -uroot
更改環境變量PATH，增加mysql絕對路徑
mysqladmin -uroot password ‘123456‘
mysql -uroot -p123456
密碼重置
vi /etc/my.cnf//增加skip-grant
重啟mysql服務 /etc/init.d/mysqld restart
mysql -uroot
use mysql;
update user set password=password(‘aminglinux‘) where user=‘root‘;
設置更改root密碼
root用戶是mysql的超級管理員用戶，和linux系統的root用戶類似，不過和Linux的不一樣 默認mysql的 root 用戶密碼是空的，直接使用mysql -uroot就可以連接上去，不需要輸入密碼，但是不安全，所以就需要設置一個密碼 為了方便使用mysql服務，將mysql目錄加入到環境變量裏"export PATH=/usr/local/mysql/bin:$PATH" 永久生效加入到"/etc/profile"裏面，執行source /etc/profile 命令
1、查看mysql是否啟動 ps aux|grep mysql，如果沒有啟動，執行"/etc/init.d/mysqld start"
[root@lnmp-server ~]# ps aux |grep mysql root 841 0.0 0.1 115432 1728 ? S 10:33 0:00 /bin/sh /usr/local/mysql/bin/mysqld_safe --datadir=/data/mysql/ --pid-file=/data/mysql//lnmp-server.pid mysql 1057 6.4 45.1 1296356 451644 ? Sl 10:33 0:04 /usr/local/mysql/bin/mysqld --basedir=/usr/local/mysql --datadir=/data/mysql --plugin-dir=/usr/local/mysql/lib/plugin --user=mysql --log-error=/var/log/mysqld.log --pid-file=/data/mysql//lnmp-server.pid --socket=/tmp/mysql.sock --port=3306 root 1231 0.0 0.0 112720 972 pts/0 R+ 10:34 0:00 grep --color=auto mysql
2、設置mysql的root密碼
安裝完mysql後，默認root用戶是沒有密碼的，我們可以通過mysql自帶的命令mysqladmin給root設置一個密碼
格式：mysqladmin -uroot passwd ‘123456‘
[root@lnmp-server ~]# mysqladmin -uroot password ‘123456‘
Warning: Using a password on the command line interface can be insecure.在設置密碼的時候，會看到有輸出信息，但這不是報錯信息，這是告訴你 你現在密碼在當前命令行顯示出來了，這樣不×××全
格式：mysqladmin -uroot -p‘123456‘ password ‘654321‘
[root@lnmp-server ~]# mysqladmin -uroot -p‘123456‘ password ‘654321‘
Warning: Using a password on the command line interface can be insecure.4、忘記密碼的情況修改
第一步：修改mysql的配置文件 /etc/my.cnf 在mysqld模塊下加入一行skip-grant,表示忽略授權
vi /etc/my.cnf #在mysqld模塊下新增一行
skip-gant
[root@lnmp-server ~]# cat /etc/my.cnf
[mysqld]
port = 3306
basedir=/usr/local/mysql
datadir=/data/mysql/
socket=/tmp/mysql.sock
user=mysql
default-time-zone=system
default-storage-engine=InnoDB
log-error=/var/log/mysqld.log
sql_mode=NO_ENGINE_SUBSTITUTION,STRICT_TRANS_TABLES
skip-grant #增加這一行第二步：在更改配置文件後，重啟mysql服務 /etc/init.d/mysqld restart
[root@lnmp-server ~]# /etc/init.d/mysqld restart
Shutting down MySQL. SUCCESS!
Starting MySQL. SUCCESS!第三步：連接mysql,這時候在輸入mysql -uroot ，會發現直接進入mysql，而不需要密碼了
[root@lnmp-server ~]# mysql -uroot
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 1
Server version: 5.6.36 Source distribution
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> 第四步：更新密碼，進入mysql後，輸入：update mysql.user set password=password(‘123456‘) where user=‘root‘;
mysql> update mysql.user set password=password(‘123456‘) where user=‘root‘;
Query OK, 0 rows affected (0.06 sec)
Rows matched: 4 Changed: 4 Warnings: 0
mysql> flush privileges; #刷新權限，讓它生效
Query OK, 0 rows affected (0.00 sec)
mysql> quit #輸入quit,退出mysql
Bye
註：提示說4行修改完畢，即使有些行是空的
第五步：更新完後修改mysql的配置文件 /etc/my.cnf 刪除增加的那一行skip-grant，去掉忽略授權，並重啟mysql服務 /etc/init.d/mysqld restart
[root@lnmp-server ~]# cat /etc/my.cnf
[mysqld]
port = 3306
basedir=/usr/local/mysql
datadir=/data/mysql/
socket=/tmp/mysql.sock
user=mysql
default-time-zone=system
default-storage-engine=InnoDB
log-error=/var/log/mysqld.log
sql_mode=NO_ENGINE_SUBSTITUTION,STRICT_TRANS_TABLES
#skip-grant #這一行刪掉或者註釋掉第六步：用更新完後密碼登陸mysql -uroot -p‘123456‘
[root@lnmp-server ~]# mysql -uroot -p‘123456‘
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 3
Server version: 5.6.36 Source distribution
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> 13.2 連接mysql
1、本地連接，默認使用sock連接
格式：mysql -uroot -p‘123456’
[root@lnmp-server ~]# mysql -uroot -p‘123456‘
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 3
Server version: 5.6.36 Source distribution
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> 2、使用ip端口連接遠程機器
格式：mysql -uroot -p‘111111‘ -h[遠程mysql主機IP] -P[端口]，mysql默認端口3306
[root@lnmp-server ~]# mysql -uroot -p‘123456‘ -h127.0.0.1 -P3306
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 Source distribution
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> 3、指定sock文件（只適合本機登陸）
格式：mysql -uroot -p‘123456‘ -S/tmp/mysql.sock
[root@lnmp-server ~]# mysql -uroot -p‘123456‘ -S/tmp/mysql.sock
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 5
Server version: 5.6.36 Source distribution
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> 4、不登陸mysql執行sql語句（常用於shell腳本）
格式：mysql -uroot -p123456 -e ‘show databases;‘
[root@lnmp-server ~]# mysql -uroot -p‘123456‘ -e ‘show databases;‘
Warning: Using a password on the command line interface can be insecure.
+--------------------+
| Database |
+--------------------+
| information_schema |
| mysql |
| performance_schema |
| test |
+--------------------+13.3 mysql常用命令
查詢庫 show databases;
切換庫 use mysql;
查看庫裏的表 show tables;
查看表裏的字段 desc tb_name;
查看建表語句 show create table tb_name\G;
查看當前用戶 select user();
查看當前使用的數據庫 select database();
創建庫 create database db1;
創建表 use db1; create table t1(id int(4), name char(40));
查看當前數據庫版本 select version();
查看數據庫狀態 show status;
查看各參數 show variables; show variables like ‘max_connect%‘;
修改參數 set global max_connect_errors=1000;
查看隊列 show processlist; show full processlist;
1、創建庫db1，並查看庫
mysql> create database db1;
Query OK, 1 row affected (0.00 sec)
mysql> show databases;
+--------------------+
| Database |
+--------------------+
| information_schema |
| db1 |
| mysql |
| performance_schema |
| test |
+--------------------+
5 rows in set (0.00 sec)2、使用db1庫,創建表tb1（新建字段id 整數型長度為4 ，字段name 字符型長度為40）,並查看表
mysql> use db1;
Database changed
mysql> create table tb1 (id int(4),name char(40));
Query OK, 0 rows affected (0.13 sec)
mysql> show tables;
+---------------+
| Tables_in_db1 |
+---------------+
| tb1 |
+---------------+
1 row in set (0.00 sec)3、查看表的字段
mysql> desc tb1;
+-------+----------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+-------+----------+------+-----+---------+-------+
| id | int(4) | YES | | NULL | |
| name | char(40) | YES | | NULL | |
+-------+----------+------+-----+---------+-------+
2 rows in set (0.00 sec)4、查看建表語句
mysql> show create table tb1\G;
*************************** 1. row ***************************
Table: tb1
Create Table: CREATE TABLE `tb1` (
`id` int(4) DEFAULT NULL,
`name` char(40) DEFAULT NULL
) ENGINE=InnoDB DEFAULT CHARSET=utf8
1 row in set (0.00 sec)
ERROR:
No query specified註：\G是為了豎型顯示，更清晰
5、查看當前用戶和庫
mysql> select user();
+----------------+
| user() |
+----------------+
| root@localhost |
+----------------+
1 row in set (0.00 sec)
mysql> select database();
+------------+
| database() |
+------------+
| db1 |
+------------+
1 row in set (0.00 sec)6、查詢數據庫版本
mysql> select version();
+-----------+
| version() |
+-----------+
| 5.6.36 |
+-----------+
1 row in set (0.00 sec)7、查看各參數 show variables; show variables like ‘max_connect%‘; // mysql下 % 為通配符
mysql> show variables like ‘max_connect%‘;
+--------------------+-------+
| Variable_name | Value |
+--------------------+-------+
| max_connect_errors | 100 |
| max_connections | 151 |
+--------------------+-------+
2 rows in set (0.00 sec)8、修改參數 set global max_connect_errors=1000; ——>僅在內存中生效，若想重啟生效修改/etc/my.cnf
mysql> set global max_connect_errors=1000;
Query OK, 0 rows affected (0.00 sec)
mysql> show variables like ‘max_connect%‘;
+--------------------+-------+
| Variable_name | Value |
+--------------------+-------+
| max_connect_errors | 1000 |
| max_connections | 151 |
+--------------------+-------+
2 rows in set (0.00 sec)9、查看隊列
show processlist; //查看庫的狀況，比如，那些用戶在連，做了些什麽操作，是否鎖表
show full processlist; //查看到的對列，最後一個會非常完成的顯示出來
mysql> show processlist;
+----+------+-----------+------+---------+------+-------+------------------+
| Id | User | Host | db | Command | Time | State | Info |
+----+------+-----------+------+---------+------+-------+------------------+
| 14 | root | localhost | db1 | Query | 0 | init | show processlist |
+----+------+-----------+------+---------+------+-------+------------------+
1 row in set (0.00 sec)
mysql> show full processlist;
+----+------+-----------+------+---------+------+-------+------------------------+
| Id | User | Host | db | Command | Time | State | Info |
+----+------+-----------+------+---------+------+-------+------------------------+
| 14 | root | localhost | db1 | Query | 0 | init | show full processlist |
+----+------+-----------+------+---------+------+-------+------------------------+
1 row in set (0.00 sec)說明：在mysql中也支持上下方向鍵查看執行過的命令，命令歷史保存在用戶家目錄下.mysql_history文件中
13.4 mysql用戶管理
1、創建一個用戶並授權所有庫和表的所有權限
格式：grant all on . to ‘user1‘ identified by ‘passwd‘;
mysql> grant all on *.* to ‘luo‘ identified by ‘123456‘;
Query OK, 0 rows affected (0.00 sec)
mysql> select user from mysql.user;
+------+
| user |
+------+
| luo |
| root |
| root |
| |
| root |
| |
| root |
+------+
7 rows in set (0.00 sec)2、針對指定的條件授權
格式：grant SELECT,UPDATE,INSERT on db1.* to ‘user2‘@‘192.168.180.1‘ identified by ‘passwd‘;
語句說明：授權查詢 更新 插入 在數據庫 db1所有表上 給來源ip為192.168.180.1的用戶user2，並設定密碼
mysql> grant SELECT,UPDATE,INSERT on db1.* to ‘user2‘@‘192.168.133.132‘ identified by ‘123456‘;
Query OK, 0 rows affected (0.00 sec)3、針對指定的條件授權
格式：grant all on db1.* to ‘user3‘@‘%‘ identified by ‘passwd‘;
語句說明：授權所有權限在數據庫 db1所有表上 給來源ip為所有的用戶user2，並設定密碼 ，%表示通配，即所有的
mysql> grant all on db1.* to ‘user2‘@‘%‘ identified by ‘123456‘;
Query OK, 0 rows affected (0.00 sec)4、show grants;
show grants；看的是root
mysql> show grants;
+----------------------------------------------------------------------------------------------------------------------------------------+
| Grants for root@localhost |
+----------------------------------------------------------------------------------------------------------------------------------------+
| GRANT ALL PRIVILEGES ON *.* TO ‘root‘@‘localhost‘ IDENTIFIED BY PASSWORD ‘*6BB4837EB74329105EE4568DDA7DC67ED2CA2AD9‘ WITH GRANT OPTION |
| GRANT PROXY ON ‘‘@‘‘ TO ‘root‘@‘localhost‘ WITH GRANT OPTION |
+----------------------------------------------------------------------------------------------------------------------------------------+
2 rows in set (0.00 sec)5、查看剛才授權的用戶user2@‘192.168.133.132‘
mysql> show grants for ‘user2‘@‘192.168.133.132‘;
+--------------------------------------------------------------------------------------------------------------------+
| Grants for [email protected] |
+--------------------------------------------------------------------------------------------------------------------+
| GRANT USAGE ON *.* TO ‘user2‘@‘192.168.133.132‘ IDENTIFIED BY PASSWORD ‘*6BB4837EB74329105EE4568DDA7DC67ED2CA2AD9‘ |
| GRANT SELECT, INSERT, UPDATE ON `db1`.* TO ‘user2‘@‘192.168.133.132‘ |
+--------------------------------------------------------------------------------------------------------------------+
2 rows in set (0.00 sec)13.5 常用sql語句
增刪改查，就是mysql和其他關系型數據庫常用的select語句操作命令
13.6 mysql數據庫備份恢復
備份庫
備份mysql庫 mysqlbak.sql文件就是mysql的備份庫文件
[root@lnmp-server ~]# mysqldump -uroot -p123456 mysql>/tmp/mysqlbak.sql
Warning: Using a password on the command line interface can be insecure.
[root@lnmp-server ~]# ll /tmp/mysqlbak.sql
-rw-r--r-- 1 root root 657033 7月 12 13:14 /tmp/mysqlbak.sql我們可以通過mysqlbak.sql來恢復數據庫，還可以恢復到另外一個數據庫裏面去
恢復庫
這裏把數據恢復到新的庫裏，創建一個新的庫mysql2
[root@lnmp-server ~]# mysql -uroot -p123456 -e "create database mysql2;"
Warning: Using a password on the command line interface can be insecure.
[root@lnmp-server ~]# mysql -uroot -p123456 mysql2 </tmp/mysqlbak.sql
Warning: Using a password on the command line interface can be insecure.進入到數據庫裏面，在後面加一個mysql2 就會進入到mysql2數據庫裏面
[root@lnmp-server ~]# mysql -uroot -p123456 mysql2
Warning: Using a password on the command line interface can be insecure.查看數據庫
mysql> select database();
+------------+
| database() |
+------------+
| mysql2 |
+------------+
1 row in set (0.00 sec)備份表
針對庫裏面的某一個表去做備份，只需要在 庫後面 加上 表名字 即可備份,先庫 在表，中間是空格
備份表格式：mysqldump -uroot -p123456 databasename tablename > /tmp/user.sql
[root@lnmp-server ~]# mysqldump -uroot -p123456 mysql user >/tmp/user.sql
Warning: Using a password on the command line interface can be insecure.恢復表
恢復表的時候，只需要寫庫的名字，不需要去寫表的名字
恢復表格式：mysql -uroot -p123456 mysql < /tmp/user.sql
[root@lnmp-server ~]# mysql -uroot -p123456 mysql </tmp/user.sql
Warning: Using a password on the command line interface can be insecure.恢復表到mysql2庫
[root@lnmp-server ~]# mysql -uroot -p123456 mysql2 </tmp/user.sql
Warning: Using a password on the command line interface can be insecure.備份所有的庫
格式：mysqldump -uroot -p123456 -A >/tmp/mysql_all.sql
-A 表示all所有的意思
[root@lnmp-server ~]# mysqldump -uroot -p111111 -A >/tmp/mysql_all.sql
Warning: Using a password on the command line interface can be insecure.只備份表結構
格式：mysqldump -uroot -p123456 -d mysql > /tmp/mysql.sql
不需要表的數據，只需要表的結構
備份mysql2的表結構
[root@lnmp-server ~]# mysqldump -uroot -p123456 -d mysql2 > /tmp/mysql2.sql
Warning: Using a password on the command line interface can be insecure.兩個機器的庫備份，一個庫備份到另一臺機器上
解決：
首先兩臺機器能夠通信
然後mysqldump -h 遠程mysql-ip -uuser-ppassword dbname > /本地backup.sql
這樣即可備份
2018-07-11