mysql常用字段类型及size大小

Life is short , play more!
本文来自lihao's Blog,转载请注明。

mysql 里各种字段类型的size大小及描述.

Ty p e S i z e D e s c r i p t i o n
CHAR[Length] Length bytes A fixed-length field from 0 to 255 characters long.
VARCHAR(Length) String length + 1 bytes A fixed-length field from 0 to 255 characters long.
TINYTEXT/TINYBLOG String length + 1 bytes A string with a maximum length of 255 characters.
TEXT/BLOB String length + 2 bytes A string with a maximum length of 65,535 characters.
MEDIUMTEXT/MEDIUMBLOB String length + 3 bytes A string with a maximum length of 16,777,215 characters.
LONGTEXT/LONGBLOB 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 65535 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 inthe 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 haveone of several possible values.
SET 1, 2, 3, 4, or 8 bytes Like ENUM except that each column can have more than one ofseveral possible values.

发表评论

电子邮件地址不会被公开。 必填项已用*标注