2018-3-22 13周4次課 MySQL常用操作（上）
默認MySQL密碼為空
[root@localhost ~]# mysql -uroot -bash: mysql: 未找到命令 [root@localhost ~]# echo $PATH /usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/root/bin [root@localhost ~]# export PATH=$PATH:/usr/local/mysql/bin/ [root@localhost ~]# echo $PATH /usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/root/bin:/usr/local/mysql/bin [root@localhost ~]# 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> quit Bye
（如果想要配置永久生效，還需將把export加入/etc/profile）
如果只是更改了profile文件，並沒有執行export PATH，那麽source /etc/profile可使環境變量生效
·設置mysql密碼：
[root@localhost ~]# mysqladmin -uroot password '123456' Warning: Using a password on the command line interface can be insecure.
（最好命令行裏不要包含密碼）
·登錄mysql：
[root@localhost ~]# mysql -uroot -p Enter password: Welcome to the MySQL monitor. Commands end with ; or \g. Your MySQL connection id is 7 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> quit Bye
·如果不知道mysql的密碼，進行密碼重置：
1，編輯 /etc/my.cnf ，增加skip-grant：
[root@localhost ~]# vi /etc/my.cnf
[root@localhost ~]# /etc/init.d/mysqld restart Shutting down MySQL.. SUCCESS! Starting MySQL.. SUCCESS!
2，進入mysql，use mysql，update user set password=password('密碼') where user='root';
[root@localhost ~]# 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> 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('123456') where user='root';
Query OK, 3 rows affected (0.00 sec)
Rows matched: 4 Changed: 3 Warnings: 0
mysql> quit
Bye3，編輯 /etc/my.cnf ，去掉skip-grant：
[root@localhost ~]# vi /etc/my.cnf
（去掉之前增加的skip-grant）
4，重啟mysql：
[root@localhost ~]# /etc/init.d/mysqld restart Shutting down MySQL.. SUCCESS! Starting MySQL. SUCCESS! root@localhost ~]# mysql -uroot -p ##可以重新登錄mysql了 Enter password: Welcome to the MySQL monitor. Commands end with ; or \g. Your MySQL connection id is 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> quit Bye
13.2 連接mysql
·連接本機MySQL：
[root@localhost ~]# mysql -uroot -p123456
·連接其他機器MySQL：
[root@localhost ~]# mysql -uroot -p123456 -h127.0.0.1 -P3306
（-h 指定ip，-P 指定端口）
·使用socket連接MySQL：
[root@localhost ~]# mysql -uroot -p123456 -S/tmp/mysql.sock
（-S 指定socket位置，只適合在本機）
·連接MySQL後進行一些操作：
[root@localhost ~]# mysql -uroot -p123456 -e "show databases"
13.3 mysql常用命令
·查詢庫 show database;
[root@localhost ~]# mysql -uroot -p123456 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 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> show databases;
·切換庫 use mysql;
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
·查看庫裏的表 show tables;
mysql> show tables;
·查看表裏的字段 desc tb_name;
mysql> desc user；
·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 databsase();
·創建庫 create database db1;
·創建表 use db1; create table t1(`id` int(4), `name` char(40));
如果想要定義其中的設置，可以
mysql> create table b1(`id`int(4),`name`char(40)) ENGINE=InnoDB DEFAULT CHARSET=utf8;
Query OK, 0 rows affected (0.01 sec)
·查看當前數據庫版本 select version();
·查看數據庫狀態 show status;
（數據不全部展示）
·查看各參數 show variables; show variables like 'max_connect%';
show variables;
（參數太多）
·修改參數 set global max_connect_errors=1000;
如果想要永久生效，需要退出到shell，vim /etc/my.cnf，定義max_connect_errors=1000;
·查看隊列 show processlist; show full processlist;
如有錯誤，歡迎指正，互相學習，共同進步！！！
2018-3-22 13周4次課 MySQL常用操作（上）