mysql基础命令详解

一、Mysql基本命令

1、登录到 Mysql 服务器

[root@server1 ~]# mysql -u root -p
Enter password: 
Welcome to the MySQL monitor.  Commands end with ; or g.
Your MySQL connection id is 19
Server version: 5.7.20 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、执行Mysql 操作语句，查看数据库中有哪些库。

mysql> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| auth               |
| mysql              |
| performance_schema |
| sys                |
+--------------------+
5 rows in set (0.00 sec)　　

3、退出Mysql 操作环境

mysql> exit
Bye
[root@server1 ~]# 

二、使用Mysql 数据库

1、查看当前使用的库中包含的表

mysql> use mysql;
Database changed
mysql> show tables;
+---------------------------+
| Tables_in_mysql           |
+---------------------------+
| columns_priv              |
| db                        |
| engine_cost               |
| event                     |
| func                      |
| general_log               |
| gtid_executed             |
| help_category             |
| help_keyword              |
| help_relation             |
| help_topic                |
| innodb_index_stats        |
| innodb_table_stats        |
| ndb_binlog_index          |
| plugin                    |
| proc                      |
| procs_priv                |
| proxies_priv              |
| server_cost               |
| 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                      |
+---------------------------+
31 rows in set (0.00 sec)　　

2、查看表的结构

mysql> describe user;
+------------------------+-----------------------------------+------+-----+-----------------------+-------+
| Field                  | Type                              | Null | Key | Default               | Extra |
+------------------------+-----------------------------------+------+-----+-----------------------+-------+
| Host                   | char(60)                          | NO   | PRI |                       |       |
| User                   | char(32)                          | NO   | PRI |                       |       |
| Select_priv            | enum('N','Y')                     | NO   |     | N                     |       |

3、创建及删除库和表

①、创建新的库

　

mysql> create database stf;
Query OK, 1 row affected (0.00 sec)

mysql> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| auth               |
| mysql              |
| performance_schema |
| stf                |
| sys                |
+--------------------+
6 rows in set (0.01 sec)　

②、创建新的表

mysql> create table sym(sym_name char(16)not null,sym_passwd char(48)default'',primary key(sym_name));
Query OK, 0 rows affected (0.02 sec)

mysql> show tables;
+---------------------------+
| Tables_in_mysql           |
+---------------------------+
| columns_priv              |
| db                        |
| engine_cost               |
| event                     |
| func                      |
| general_log               |
| gtid_executed             |
| help_category             |
| help_keyword              |
| help_relation             |
| help_topic                |
| innodb_index_stats        |
| innodb_table_stats        |
| ndb_binlog_index          |
| plugin                    |
| proc                      |
| procs_priv                |
| proxies_priv              |
| server_cost               |
| servers                   |
| slave_master_info         |
| slave_relay_log_info      |
| slave_worker_info         |
| slow_log                  |
| sym                       |
| tables_priv               |
| time_zone                 |
| time_zone_leap_second     |
| time_zone_name            |
| time_zone_transition      |
| time_zone_transition_type |
| user                      |
+---------------------------+
32 rows in set (0.00 sec)　　

③、删除一个数据表

mysql> drop table mysql.sym;
Query OK, 0 rows affected (0.00 sec)

mysql> 　　

④、删除一个数据库

mysql> drop database stf;
Query OK, 0 rows affected (0.00 sec)

mysql> 

4、管理表中的数据记录

首先创建一个stf库和sym表。

mysql> create database stf;
Query OK, 1 row affected (0.00 sec)

mysql> use stf;
Database changed
mysql> create table sym(sym_name char(16)not null,sym_passwd char(48)default'',primary key(sym_name));
Query OK, 0 rows affected (0.01 sec)

mysql> 

　　

①、插入数据记录

insert into 语句：用于向表中插入新的数据记录

执行以下操作会将stf 库中的sym 表插入一条记录：用户名为“zhangsan”，对应的密码为‘123457’。

mysql> insert into sym(sym_name,sym_passwd)values('zhangsan',password('123457'));
Query OK, 1 row affected, 1 warning (0.00 sec)

mysql> 　　

②、查询数据记录

mysql> select * from stf.sym;
+----------+-------------------------------------------+
| sym_name | sym_passwd                                |
+----------+-------------------------------------------+
| zhangsan | *F13F0EEE74714A1A9922D61FC15789AD75FE4958 |
+----------+-------------------------------------------+
1 row in set (0.00 sec)　　

当需要根据特定的条件查找记录时，where条件语句是必不可少的，例如若要在sym表中用户名为zhangsan的记录，可执行以下操作

mysql> select sym_name,sym_passwd from stf.sym where sym_name='zhangsan';
+----------+-------------------------------------------+
| sym_name | sym_passwd                                |
+----------+-------------------------------------------+
| zhangsan | *F13F0EEE74714A1A9922D61FC15789AD75FE4958 |
+----------+-------------------------------------------+
1 row in set (0.00 sec)　　

 ③、修改数据记录

update：用于修改、更新表中的数据记录。

mysql> update stf.sym set sym_passwd=password('')where sym_name='zhangsan';
Query OK, 1 row affected (0.00 sec)
Rows matched: 1  Changed: 1  Warnings: 0

mysql> select * from stf.sym;
+----------+------------+
| sym_name | sym_passwd |
+----------+------------+
| zhangsan |            |
+----------+------------+
1 row in set (0.00 sec)　　

④、修改数据库密码

[root@server1 ~]# mysqladmin -uroot -p password '931106'
Enter password: 
mysqladmin: [Warning] Using a password on the command line interface can be insecure.
Warning: Since password will be sent to server in plain text, use ssl connection to ensure password safety.　　

⑤、删除数据记录

delete：用于删除表中数据记录。

mysql> delete from stf.sym where sym_name='zhangsan';
Query OK, 1 row affected (0.00 sec)

mysql> select * from stf.sym;
Empty set (0.00 sec）