数字

整数数据类型

基本整数数字数据类型。

名称	别名	存储大小	最小值	最大值	Description
TINYINT	INT8	1 字节	-128	127
SMALLINT	INT16	2 字节	-32768	32767
INT	INT32	4 字节	-2147483648	2147483647
BIGINT	INT64	8 字节	-9223372036854775808	9223372036854775807

tip

如果你想要无符号整数，请使用 UNSIGNED 约束，这与 MySQL 兼容，例如：

CREATE TABLE test_numeric(tiny TINYINT, tiny_unsigned TINYINT UNSIGNED)

浮点数据类型

基本的 Float32/Float64 数据类型。

名称	别名	存储大小	最小值	最大值	Description
FLOAT		4 字节	-3.40282347e+38	3.40282347e+38
DOUBLE		8 字节	-1.7976931348623157E+308	1.7976931348623157E+308

函数

查看 数字函数。

Examples

CREATE TABLE test_numeric
(
    tiny              TINYINT,
    tiny_unsigned     TINYINT UNSIGNED,
    smallint          SMALLINT,
    smallint_unsigned SMALLINT UNSIGNED,
    int               INT,
    int_unsigned      INT UNSIGNED,
    bigint            BIGINT,
    bigint_unsigned   BIGINT UNSIGNED,
    float             FLOAT,
    double            DOUBLE
);

DESC test_numeric;
+-------------------+-------------------+------+---------+-------+
| Field             | Type              | Null | Default | Extra |
+-------------------+-------------------+------+---------+-------+
| tiny              | TINYINT           | NO   | 0       |       |
| tiny_unsigned     | TINYINT UNSIGNED  | NO   | 0       |       |
| smallint          | SMALLINT          | NO   | 0       |       |
| smallint_unsigned | SMALLINT UNSIGNED | NO   | 0       |       |
| int               | INT               | NO   | 0       |       |
| int_unsigned      | INT UNSIGNED      | NO   | 0       |       |
| bigint            | BIGINT            | NO   | 0       |       |
| bigint_unsigned   | BIGINT UNSIGNED   | NO   | 0       |       |
| float             | FLOAT             | NO   | 0       |       |
| double            | DOUBLE            | NO   | 0       |       |
+-------------------+-------------------+------+---------+-------+