更改mysql数据库的root密码
修改root密码命令为
/usr/local/mysql/bin/mysql -uroot定义环境变量
临时定义环境变量
export PATH=$PATH:/usr/local/mysql/bin/ //临时定义环境变量
echo $PATH //显示环境变量
/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/tmp/:/root/bin:/usr/local/mysql/bin/永久定义环境变量
vim /etc/profile
增加代码
export PATH=$PATH:/usr/local/mysql/bin/source /etc/profile //生效文件登录MySQL
指定使用账号root密码登录，-u后面为账号，-p后面可以跟密码；
mysql -uroot -p
mysql -uroot -p‘123456789‘设置密码
在空密码下指定密码为123456
mysqladmin -uroot password ‘123456‘;在有密码的情况下修改密码
旧密码123456修改为123456789
mysqladmin -uroot -p‘123456‘ password ‘123456789‘忘记root密码
编辑配置文件
vim /etc/my.cnf在[mysqld]下增加一行skip-grant
预览
[mysqld]
skip-grant //跳过密码验证
datadir=/data/mysql
socket=/tmp/mysql.sock重启mysql服务
/etc/init.d/mysqld restart登录mysql修改
mysql -uroot
use mysql;
update user set password=password(‘123456‘) where user=‘root‘;取消配置文件配置
vim /etc/my.cnf
取消代码
skip-grant重启mysql服务
/etc/init.d/mysqld restart测试验证
mysql -uroot -p‘123456‘
使用密码123456登录成功连接MySQL
常用的连接命令
mysql -uroot -p‘123456‘ //连接本机
mysql -uroot -p‘123456‘ -h127.0.0.1 -P3306 //连接远程机器127.0.0.1为ip，3306为端口
mysql -uroot -p‘123456‘ -S/tmp/mysql.sock //使用sock方式连接，只适合本机连接
mysql -uroot -p‘123456‘ -e "show databases" //列出mysql的所有数据库，用于shell命令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 |
+--------------------+MySQL常用命令
必须登录mysql才能使用的命令
使用命令后面必须加；号
查询库 show databases;
切换库 use mysql;
查看库里的表 show tables;
查看表里的字段 desc tb_name;
查看建表语句 show create table tb_name\G;
查看当前用户 select user();
查看当前使用的数据库 select database();
创建库 create database db1;
创建表 use db1; create table t1(idint(4),namechar(40));
查看当前数据库版本 select version();
查看数据库状态 show status;
查看各参数 show variables; show variables like ‘max_connect%‘;
修改参数 set global max_connect_errors=1000;
查看队列 show processlist; show full processlist;
查询库
mysql> show databases;
+--------------------+
| Database |
+--------------------+
| information_schema |
| mysql |
| performance_schema |
| test |
+--------------------+
4 rows in set (0.00 sec)切换库
mysql> use mysql；
Database changed查看库里面的表
mysql> show tables;
+---------------------------+
| Tables_in_mysql |
+---------------------------+
| columns_priv |
| db |
| event |
| func |
| general_log |
| help_category |
| help_keyword |
| help_relation |
| help_topic |
| innodb_index_stats |
| innodb_table_stats |
| ndb_binlog_index |
| plugin |
| proc |
| procs_priv |
| proxies_priv |
| servers |
| slave_master_info |
| slave_relay_log_info |
| slave_worker_info |
| slow_log |
| tables_priv |
| time_zone |
| time_zone_leap_second |
| time_zone_name |
| time_zone_transition |
| time_zone_transition_type |
| user |
+---------------------------+
28 rows in set (0.00 sec)查看表里面的字段
注意：格式是
desc [表名];
desc user;
mysql> desc user;
+------------------------+-----------------------------------+------+-----+-----------------------+-------+
| Field | Type | Null | Key | Default | Extra |
+------------------------+-----------------------------------+------+-----+-----------------------+-------+
| Host | char(60) | NO | PRI | | |
| User | char(16) | NO | PRI | | |
| Password | char(41) | NO | | | |
| Select_priv | enum(‘N‘,‘Y‘) | NO | | N | |
| Insert_priv | enum(‘N‘,‘Y‘) | NO | | N | |
| Update_priv | enum(‘N‘,‘Y‘) | NO | | N | |
| Delete_priv | enum(‘N‘,‘Y‘) | NO | | N | |
| Create_priv | enum(‘N‘,‘Y‘) | NO | | N | |
| Drop_priv | enum(‘N‘,‘Y‘) | NO | | N | |
| Reload_priv | enum(‘N‘,‘Y‘) | NO | | N | |
| Shutdown_priv | enum(‘N‘,‘Y‘) | NO | | N | |
| Process_priv | enum(‘N‘,‘Y‘) | NO | | N | |
| File_priv | enum(‘N‘,‘Y‘) | NO | | N | |
| Grant_priv | enum(‘N‘,‘Y‘) | NO | | N | |
| References_priv | enum(‘N‘,‘Y‘) | NO | | N | |
| Index_priv | enum(‘N‘,‘Y‘) | NO | | N | |
| Alter_priv | enum(‘N‘,‘Y‘) | NO | | N | |
| Show_db_priv | enum(‘N‘,‘Y‘) | NO | | N | |
| Super_priv | enum(‘N‘,‘Y‘) | NO | | N | |
| Create_tmp_table_priv | enum(‘N‘,‘Y‘) | NO | | N | |
| Lock_tables_priv | enum(‘N‘,‘Y‘) | NO | | N | |
| Execute_priv | enum(‘N‘,‘Y‘) | NO | | N | |
| Repl_slave_priv | enum(‘N‘,‘Y‘) | NO | | N | |
| Repl_client_priv | enum(‘N‘,‘Y‘) | NO | | N | |
| Create_view_priv | enum(‘N‘,‘Y‘) | NO | | N | |
| Show_view_priv | enum(‘N‘,‘Y‘) | NO | | N | |
| Create_routine_priv | enum(‘N‘,‘Y‘) | NO | | N | |
| Alter_routine_priv | enum(‘N‘,‘Y‘) | NO | | N | |
| Create_user_priv | enum(‘N‘,‘Y‘) | NO | | N | |
| Event_priv | enum(‘N‘,‘Y‘) | NO | | N | |
| Trigger_priv | enum(‘N‘,‘Y‘) | NO | | N | |
| Create_tablespace_priv | enum(‘N‘,‘Y‘) | NO | | N | |
| ssl_type | enum(‘‘,‘ANY‘,‘X509‘,‘SPECIFIED‘) | NO | | | |
| ssl_cipher | blob | NO | | NULL | |
| x509_issuer | blob | NO | | NULL | |
| x509_subject | blob | NO | | NULL | |
| max_questions | int(11) unsigned | NO | | 0 | |
| max_updates | int(11) unsigned | NO | | 0 | |
| max_connections | int(11) unsigned | NO | | 0 | |
| max_user_connections | int(11) unsigned | NO | | 0 | |
| plugin | char(64) | YES | | mysql_native_password | |
| authentication_string | text | YES | | NULL | |
| password_expired | enum(‘N‘,‘Y‘) | NO | | N | |
+------------------------+-----------------------------------+------+-----+-----------------------+-------+
43 rows in set (0.00 sec)查看创建表的语句
show create table user\G;
查看当前用户
select user();
mysql> select user();
+----------------+
| user() |
+----------------+
| [email protected] |
+----------------+
1 row in set (0.00 sec)查看当前使用的数据库
select database();
mysql> select database();
+------------+
| database() |
+------------+
| mysql |
+------------+
1 row in set (0.00 sec)创建库
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)创建表
use db1; //切换到db1库
create table t1(`id` int(4),`name` char(40)); //注意：中间使用的是反引号，创建表t1查看数据库版本
mysql> select version();
+-----------+
| version() |
+-----------+
| 5.6.36 |
+-----------+
1 row in set (0.00 sec)查看数据库状态
show status;
查看参数
show variables;
show variables like ‘max_connect%‘; //模糊查询max_connect，后面必须加%
set global max_connect_errors=1000; //修改max_connect_errors参数为1000查看队列
show processlist;
show full processlist; //查看哪些用户在连接数据库（完整版）原文地址：http://blog.51cto.com/shuzonglu/2090108
时间： 2024-08-01 17:20:56