转 MYSQL 基本数据类型

最新推荐文章于 2024-09-05 20:09:31 发布

转载最新推荐文章于 2024-09-05 20:09:31 发布 · 905 阅读

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本文详细介绍了MySQL中的各种数据类型及其特点，包括字符类型如CHAR、VARCHAR等，数值类型如TINYINT、INT、BIGINT等，浮点数类型如FLOAT、DOUBLE等，日期时间类型如DATE、DATETIME等，以及特殊类型如ENUM、SET等。

MySQL Data Types
TYPE	SIZE	DESCRIPTION
CHAR[Length]	Length bytes	A fixed-length field from 0 to 255 characters long
VARCHAR[Length]	String length + 1 bytes	A variable-length field from 0 to 255 characters long
TINYTEXT	String length + 1 bytes	A string with a maximum length of 255 characters
TEXT	String length + 2 bytes	A string with a maximum length of 65,535 characters
MEDIUMTEXT	String length + 3 bytes	A string with a maximum length of 16,777,215 characters
LONGTEXT	String length + 4 bytes	A string with a maximum length of 4,294,967,295 characters
TINYINT[Length]	1 byte	Range of 128 to 127 or 0 to 255 unsigned
SMALLINT[Length]	2 bytes	Range of 32,768 to 32,767 or 0 to 65,535 unsigned
MEDIUMINT[Length]	3 bytes	Range of 8,388,608 to 8,388,607 or 0 to 16,777,215 unsigned
INT[Length]	4 bytes	Range of 2,147,483,648 to 2,147,483,647 or 0 to 4,294,967,295 unsigned
BIGINT[Length]	8 bytes	Range of 9,223,372,036,854,775,808 to 9,223,372,036,854,775,807 or 0 to 18,446,744,073,709,551,615 unsigned
FLOAT	4 bytes	A small number with a floating decimal point
DOUBLE[Length, Decimals]	8 bytes	A large number with a floating decimal point
DECIMAL[Length, Decimals]	Length + 1 or Length + 2 bytes	A DOUBLE stored as a string, allowing for a fixed decimal point
DATE	3 bytes	In the format of YYYY-MM-DD
DATETIME	8 bytes	In the format of YYYY-MM-DD HH:MM:SS
TIMESTAMP	4 bytes	In the format of YYYYMMDDHHMMSS; acceptable range ends in the year 2037
TIME	3 bytes	In the format of HH:MM:SS
ENUM	1 or 2 bytes	Short for enumeration, which means that each column can have one of several possible values
SET	1, 2, 3, 4, or 8 bytes	Like ENUM except that each column can have more than one of several possible values