MySQL手册 2-阿里云开发者社区

MySQL的基本操作

\G 表示查询结果进行按列打印,横向坐标纵向打印

show database; 列出数据库列表

use 数据库名称; 选择要操作的数据库

show tables;列出数据库所有表

show columns from 表名称;显示数据表的属性

show index from 数据表;显示数据表的详细索引信息

MySQL数据库的操作创建数据库

1 create database 数据库名称; 创建数据库

删除数据库

1 drop database 数据库名称;删除数据库

选择数据库

1 use 数据库名称;选择数据库

查询全部数据库

1 show databases; 查询全部数据库
2
3 mysql> show databases;
4 +--------------------+
5 | Database |
6 +--------------------+
7 | information_schema |
8 | mysql |
9 | performance_schema |
10 | sys |
11 +--------------------+
12 4 rows in set (0.00 sec)
13

查询创建数据库的语句

1 mysql> show create database xiaole;
2 +----------+-----------------------------------------------------------------+
3 | Database | Create Database |
4 +----------+-----------------------------------------------------------------+
5 | xiaole | CREATE DATABASE `xiaole` /*!40100 DEFAULT CHARACTER SET utf8 */ |
6 +----------+-----------------------------------------------------------------+
7 1 row in set (0.00 sec)
8
9 Create Database 里面就是创建数据库的语句
10
11 
12
13

MySQL用户管理

1 use mysql; 切换到mysql数据库
2
3
4 #添加用户
5 MariaDB [(none)]> create user 'xiaole'@'%' identified by 'xiaole521';
6 Query OK, 0 rows affected (0.00 sec)
7
8 xiaole 是用户名
9 % 是指定登录 %是代表全部地址都可以登录 localhost是本地登录
10 xiaole521 是密码
11
12 
13 MariaDB [mysql]> flush privileges; 刷新权限
14 Query OK, 0 rows affected (0.00 sec)
15
16
17 查询用户
18 select host, user, password from user where user='xiaole';
19
20
21 #删除用户
22 MariaDB [mysql]> delete from user where user='xiaole';
23 Query OK, 1 row affected (0.00 sec)
24
25 xiaole是用户
26
27

数据表的操作

创建数据表

1 create table if not exists `name`(
2 `id` int auto_increment,
3 `name` varchar(200) not null comment '名称',
4 `age` int(3) not null comment '年龄',
5 primary key (`id`)
6 )engine=InnoDB default charset=utf8;
7 
8 CREATE TABLE `user` (
9 `id` INT(11) AUTO_INCREMENT,
10 `user` VARCHAR(16) NOT NULL,
11 `password` VARCHAR(16) NOT NULL ,
12 PRIMARY KEY (`id`)
13 ) ENGINE=INNODB DEFAULT CHARSET=utf8;

name是表名

id是字段

auto_increment是设置自动增长从1开始增长

primary key是设置主键

engine是设置存储引擎

charset是设置编码修改表

向数据表添加字段

1 alter table 表名 add column 字段名称 varchar(16) not null comment '这是我添加的字段';
2
3 mysql> alter table user add column userxiaoletest varchar(16) not null comment '这是我添
加的字段';
4 Query OK, 0 rows affected (0.02 sec)
5 Records: 0 Duplicates: 0 Warnings: 0
6
7 mysql> show full columns from user;
8 +----------------+-------------+-----------------+------+-----+---------+--------------
--+---------------------------------+--------------------------------+
9 | Field | Type | Collation | Null | Key | Default | Extra 
 | Privileges | Comment |
10 +----------------+-------------+-----------------+------+-----+---------+--------------
--+---------------------------------+--------------------------------+
11 | id | int(11) | NULL | NO | PRI | NULL |
auto_increment | select,insert,update,references | |
12 | user | varchar(16) | utf8_general_ci | NO | | NULL | 
 | select,insert,update,references | 用户名 |
13 | password | varchar(16) | utf8_general_ci | YES | | 123456 | 
 | select,insert,update,references | 密码如果不填默认123456 |
14 | usertest | varchar(16) | utf8_general_ci | YES | | NULL | 
 | select,insert,update,references | |
15 | userxiaole | varchar(16) | utf8_general_ci | NO | | NULL | 
 | select,insert,update,references | 这是我添加的字段 |
16 | userxiaoletest | varchar(16) | utf8_general_ci | NO | | NULL | 
 | select,insert,update,references | 这是我添加的字段 |
17 +----------------+-------------+-----------------+------+-----+---------+--------------
--+---------------------------------+--------------------------------+
18 6 rows in set (0.02 sec)
19

修改数据表结构

1 alter table 表名 modify 字段 int not null comment '这是我修改的数据表';
2
3 mysql> alter table user modify userxiaoletest int not null comment '这是我修改的数据表';
4 Query OK, 0 rows affected (0.01 sec)
5 Records: 0 Duplicates: 0 Warnings: 0
6
7 mysql> show full columns from user;
8 +----------------+-------------+-----------------+------+-----+---------+--------------
--+---------------------------------+--------------------------------+
9 | Field | Type | Collation | Null | Key | Default | Extra 
 | Privileges | Comment |
10 +----------------+-------------+-----------------+------+-----+---------+--------------
--+---------------------------------+--------------------------------+
11 | id | int(11) | NULL | NO | PRI | NULL |
auto_increment | select,insert,update,references | |
12 | user | varchar(16) | utf8_general_ci | NO | | NULL | 
 | select,insert,update,references | 用户名 |
13 | password | varchar(16) | utf8_general_ci | YES | | 123456 | 
 | select,insert,update,references | 密码如果不填默认123456 |
14 | usertest | varchar(16) | utf8_general_ci | YES | | NULL | 
 | select,insert,update,references | |
15 | userxiaole | varchar(16) | utf8_general_ci | NO | | NULL | 
 | select,insert,update,references | 这是我添加的字段 |
16 | userxiaoletest | int(11) | NULL | NO | | NULL | 
 | select,insert,update,references | 这是我修改的数据表 |
17 +----------------+-------------+-----------------+------+-----+---------+--------------
--+---------------------------------+--------------------------------+
18 6 rows in set (0.01 sec)
19

删除表中字段

1 alter table 表名称 drop column 要删除的字段;
2
3 mysql> alter table user drop column userxiaoletest;
4 Query OK, 0 rows affected (0.02 sec)
5 Records: 0 Duplicates: 0 Warnings: 0
6
7 mysql> show full columns from user;
8 +------------+-------------+-----------------+------+-----+---------+----------------+-
--------------------------------+--------------------------------+
9 | Field | Type | Collation | Null | Key | Default | Extra |
Privileges | Comment |
10 +------------+-------------+-----------------+------+-----+---------+----------------+-
--------------------------------+--------------------------------+
11 | id | int(11) | NULL | NO | PRI | NULL | auto_increment |
select,insert,update,references | |
12 | user | varchar(16) | utf8_general_ci | NO | | NULL | |
select,insert,update,references | 用户名 |
13 | password | varchar(16) | utf8_general_ci | YES | | 123456 | |
select,insert,update,references | 密码如果不填默认123456 |
14 | usertest | varchar(16) | utf8_general_ci | YES | | NULL | |
select,insert,update,references | |
15 | userxiaole | varchar(16) | utf8_general_ci | NO | | NULL | |
select,insert,update,references | 这是我添加的字段 |
16 +------------+-------------+-----------------+------+-----+---------+----------------+-
--------------------------------+--------------------------------+
17 5 rows in set (0.01 sec)
18
19 mysql>
20

更改表名

1 rename table 要修改的表名 to 修改成的名字;
2
3 mysql> rename table user to username;
4 Query OK, 0 rows affected (0.01 sec)
5
6 mysql> show tables; #查询全部表
7 +--------------------+
8 | Tables_in_test-txt |
9 +--------------------+
10 | username |
11 +--------------------+
12 1 row in set (0.01 sec)
13

删除数据表

1 drop table 要删除的数据表;

查询数据表结构

1 desc user; 查询表结构
2
3 mysql> desc user;
4 +----------+-------------+------+-----+---------+----------------+
5 | Field | Type | Null | Key | Default | Extra |
6 +----------+-------------+------+-----+---------+----------------+
7 | id | int(11) | NO | PRI | NULL | auto_increment |
8 | user | varchar(16) | NO | | NULL | |
9 | password | varchar(16) | YES | | 123456 | |
10 +----------+-------------+------+-----+---------+----------------+
11 3 rows in set (0.01 sec)
12
13 show columns from 表名称;
14 mysql> show columns from user;
15 +----------+-------------+------+-----+---------+----------------+
16 | Field | Type | Null | Key | Default | Extra |
17 +----------+-------------+------+-----+---------+----------------+
18 | id | int(11) | NO | PRI | NULL | auto_increment |
19 | user | varchar(16) | NO | | NULL | |
20 | password | varchar(16) | YES | | 123456 | |
21 +----------+-------------+------+-----+---------+----------------+
22 3 rows in set (0.01 sec)
23
24
25 show full columns from 表名称;
26
27 mysql> show full columns from user;
28 +----------+-------------+-----------------+------+-----+---------+----------------+---
------------------------------+--------------------------------+
29 | Field | Type | Collation | Null | Key | Default | Extra |
Privileges | Comment |
30 +----------+-------------+-----------------+------+-----+---------+----------------+---
------------------------------+--------------------------------+
31 | id | int(11) | NULL | NO | PRI | NULL | auto_increment |
select,insert,update,references | |
32 | user | varchar(16) | utf8_general_ci | NO | | NULL | |
select,insert,update,references | 用户名 |
33 | password | varchar(16) | utf8_general_ci | YES | | 123456 | |
select,insert,update,references | 密码如果不填默认123456 |
34 +----------+-------------+-----------------+------+-----+---------+----------------+---
------------------------------+--------------------------------+
35 3 rows in set (0.01 sec)
36 #full 是更详细的显示、
37
38 Key 表的索引
39 Collation 字符集和字符列排序规则 
40 Privileges 权限
41 Comment 解释

MySQL手册 2

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