MySQL use the integer type
From -2 ^ 63 (-9223372036854775808) to 2 ^ 63-1 (9223372036854775807) integer data (all numbers). Storage size is 8 bytes.
P.S. bigint has a length, length built in mysql table, just for display digits
From -2 ^ 31 (2,147,483,648) to 2 ^ 31--1 (2,147,483,647) integer data (all numbers). Storage size is 4 bytes. int The SQL-92 synonyms for the integer.
From -2 ^ 15 (-32,768) to 2 ^ 15--1 (32,767) integer data. Storage size is 2 bytes.
From 0-255 integer data. Storage size is 1 byte.
In support of local support bigint integer data types. However, bigint for some special cases, when an integer value exceeds the range supported by the int data type, you can use bigint. In SQL Server, int data type is the primary integer data type.
In the Data Type priorities table, bigint located between smallmoney and int.
Only when the parameter expression is bigint data type, the function does not return bigint. SQL Server does not automatically other integer data types (tinyint, smallint and int) promoted to bigint.
int (M) in the integer data types, M indicates the maximum display width. In int (M), M is the value with int (M) occupied much storage does not have any relationship. And digits are unrelated int (3), int (4), int (8) on a disk are occupied by 4 btyes storage space.