mysql Data Type: integer type

TINYINT             8位

SMALLINT         16位

MEDIUMINT 24 Wei

INT 32 bit

BIGINT 64 Wei

Values ​​in the range -2 (N-1) to 2 (N-1) -1 where N is the number of bits stored

There UNSIGED integer type attribute indicates no negative 

But this can be no real meaning it will not be worth the legal limit in the range of specified width integer types such as INT (11) for storing calculated for INT (1) and INT (20) are the same