Database staff handy series: Mysql field length _ MySQL

Storage required for column type TINYINT1 byte SMALLINT2 MEDIUMINT3 byte INT4 byte INTEGER4 byte BIGINT8 byte FLOAT (X) 4 If XFLOAT4 byte DOUBLE8 byte DOUBLEPRECISION8 byte REAL8 byte DECIMAL (M, D) M byte (D + 2, if MNUMERIC (M, D column type requires storage capacity
　　
TINYINT 1 byte
　　
SMALLINT 2 bytes
　　
MEDIUMINT 3 bytes
　　
INT 4 bytes
　　
INTEGER 4 bytes
　　
BIGINT 8 bytes
　　
FLOAT (X) 4 if X <= 24 or 8 if 25 <= X <= 53
　　
FLOAT 4 bytes
　　
DOUBLE 8 bytes
　　
Double precision 8 bytes
　　
REAL 8 bytes
　　
DECIMAL (M, D) M bytes (D + 2, if M <D)
　　
NUMERIC (M, D) M bytes (D + 2, if M <D)
　　
Date and time type
　　
Storage required for column types
　　
DATE 3 bytes
　　
DATETIME 8 bytes
　　
TIMESTAMP 4 bytes
　　
TIME 3 bytes
　　
YEAR 1 byte
　　
String type
　　
Storage required for column types
　　
CHAR (M) M bytes, 1 <= M <= 255
　　
VARCHAR (M) L + 1 byte, where L <= M and 1 <= M <= 255
　　
TINYBLOB, tinytext l + 1 byte, here L <2 ^ 8
　　
BLOB, text l + 2 bytes, here L <2 ^ 16
　　
MEDIUMBLOB, mediumtext l + 3 bytes, here L <2 ^ 24
　　
LONGBLOB, longtext l + 4 bytes, here L <2 ^ 32
　　
ENUM ('value1 ', 'value2',...) 1 or 2 bytes, depending on the number of enumerated values (maximum 65535)
　　
SET ('value1 ', 'value2',...) 1, 2, 3, 4, or 8 bytes, depending on the number of SET members (up to 64 members)