PHP移动互联网开发笔记(6)??MySQL数据库基础回顾
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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