SQL Server several error-prone data types

bigint integer data (all numbers) from -2^63 (-9223372036854775808) to 2^63-1 (9223372036854775807). The storage size is 8 bytes.

int from -2^31 (-2,147,483,648) to 2^31-1 (2,147,483,647) of integer data (all numbers). The storage size is 4 bytes. The SQL-92 synonym for int is integer.

smallint integer data from -2^15 (-32,768) to 2^15-1 (32,767). The storage size is 2 bytes.

Tinyint the integer data from 0 to 255. The storage size is 1 bytes.

Supports bigint data types where integer values are supported. However, bigint is used in some special cases where the integer value exceeds the range supported by the INT data type, and the bigint can be used.

In SQL Server, the int data type is the primary integer data type. In the data type precedence table, bigint is located between smallmoney and Int. A function returns bigint only if the parameter expression is a bigint data type. SQL Server does not automatically promote other integer data types (tinyint, smallint, and int) to bigint