MySQL中数据类型详解

1、数值类型：
BIT[(M)]
二进制位,M指定值的位数,从1到64(也就是说它能定义任意的介于1到64位之间的整数),如某字段的类型定义为BIT或BIT[1],它就只能取0或1,定义为BIT[2]只能取0~3之间的整数,如果没有指定M则默认M=1.

TINYINT[(M)] [UNSIGNED] [ZEROFILL]
8位整数,有符号数的取值范围是-128到127,无符号数的取值范围是0到255(此处M的取值范围是0到255,是用来控制显示宽度的,但实际上好像没用,区别BIT(M).)

BOOL,BOLLEAN
与TINYINT(1)同义.零被认为是false,非零数被认为是true.

SMALLINT[(M)] [UNSIGNED] [ZEROFILL]
16位整数,有符号数的取值范围为-32768到32767,无符号数的取值范围是0到65535.

MEDIUMINT[(M)] [UNSIGNED] [ZEROFILL]
24位整数,有符号数取值范围是-8388608到8388607,无符号数的取值范围是0到16777215.

INT[(M)] [UNSIGNED] [ZEROFILL]
32位整数,有符号数的取值范围是-2147483648到2147483647,无符号数的取值范围是0到4294967295.

INTERGER[(M)] [UNSIGNED] [ZEROFILL]
同INT.

BIGINT[(M)] [UNSIGNED] [ZEROFILL]
64位整数,有符号数的取值范围是-9223372036854775808到9223372036854775807,无符号的取值范围是0到18446744073709551615.

二、日期和时间类型

三、字符(串)类型

English from MySQL 5.0 Reference Manual:
1. Overview of Numeric Types

BIT[(
M
)]

A bit-field type.

M

indicates the number of bits per value, from 1 to 64. The default is 1 if

M

is omitted.

This data type was added in MySQL 5.0.3 for

MyISAM

, and extended in 5.0.5 to

MEMORY

,

InnoDB

, and

BDB

. Before 5.0.3,

BIT

is a synonym for

TINYINT(1)

.

TINYINT[(
M
)] [UNSIGNED] [ZEROFILL]

A very small integer. The signed range is

-128

to

127

. The unsigned range is

0

to

255

.

BOOL

,

BOOLEAN

These types are synonyms for

TINYINT(1)

. A value of zero is considered false. Non-zero values are considered true.

In the future, full boolean type handling will be introduced in accordance with standard SQL.

SMALLINT[(
M
)] [UNSIGNED] [ZEROFILL]

A small integer. The signed range is

-32768

to

32767

. The unsigned range is

0

to

65535

.

MEDIUMINT[(
M
)] [UNSIGNED] [ZEROFILL]

A medium-sized integer. The signed range is

-8388608

to

8388607

. The unsigned range is

0

to

16777215

.

INT[(
M
)] [UNSIGNED] [ZEROFILL]

A normal-size integer. The signed range is

-2147483648

to

2147483647

. The unsigned range is

0

to

4294967295

.

INTEGER[(
M
)] [UNSIGNED] [ZEROFILL]

This type is a synonym for

INT

.

BIGINT[(
M
)] [UNSIGNED] [ZEROFILL]

A large integer. The signed range is

-9223372036854775808

to

9223372036854775807

. The unsigned range is

0

to

18446744073709551615

.