Home Backend Development PHP Tutorial PHP移动互联网开发笔记(6)??MySQL数据库基础回顾

PHP移动互联网开发笔记(6)??MySQL数据库基础回顾

Jun 23, 2016 pm 01:57 PM
php review develop database notes

最近看了一些架构方面的资料,但是发现基础知识都不怎么牢固,接下来的一段时间,我会定期总结基础知识。

一、数据类型

 

1、整型

 

数据类型 存储空间 说明 取值范围
TINYINT 1字节 非常小的整数 带符号值:-128~127
无符号值:0~255
SMALLINT 2字节 较小的整数 带符号值:-32768~32767
无符号值:0~65535
MEDIUMNT 3字节 中等大小的整数 带符号值:-8388608~8388607
无符号值:0~16777215
INT 4字节 标准整数 带符号值:-2147483648~2147483647
无符号值:0~4294967295
BIGINT 8字节 大整数  

 

2、浮点型

 

数据类型 存储空间 说明 取值范围
FLOAT 4字节 但精度浮点数  
DOUBLE 8字节 双精度浮点数  
DECIMAL(M,D) 自定义 以字符串形式表示  

 

3、字符串类型

 

类型 存储空间 说明 最大长度
Char[(M)] M字节 定长字符串 M字节
Varchar[(M)] L+1字节 可变长字符串 M字节
tinyblog,tingtext L+1字节 非常小的blob和文本串 2^8字符
blog,text L+2字节 小BLOB和文本串 2^16-1字节
mediumblob,mediumtext L+3字节 中等的BLOB和文本串 2^24字节
longblob,longtext L+4字节 大BLOB和文本串 2^32-1字节
enum('value','value') 1或2字节 枚举:可赋予某个枚举成员 65535个成员
set('value', 'value') 1,2,3,4或8字节 集合:可赋予多个集合成员 64个成员

4、日期和时间型数据

 

 

类型 存储空间 说明 最大长度
Date 3字节 YYYY-MM-DD格式表示 1000-01-01~9999-12-31
TIME 3字节 hh:mm:ss格式表示时间值 -838:59:59~838:59:59
DATETIME 8字节 YYYY-MM-DD  hh:mm:ss格式  
TIMESTAMP 4字节 YYYYMMDDhhmmss格式表示时间戳  
YEAR 1字节 YYYY格式的年份值 1901~2155

 

二、MySQL数据库的操作

1、登录数据库

mysql 参数

-D,--database=name 打开指定数据库

--delimiter=name 指定分隔符

-E,--vertical 垂直显示结果

-h,--host=name 服务器名称

-H,--html 提供HTML输出

-X,--xml 提供XML输出

-p,--password[=name]密码

-P,--port=# 端口号

--prompt=name 设置提示符

-u,--user=name 用户名

-V,--version 输出版本信息并退出

mysql -h 服务器主机地址 -u 用户名 -p 用户密码

2、退出登录

exit

quit

\q

3、修改密码

4、创建选择及查看数据库

创建数据库

选择数据库

删除数据库中的内容

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