Difference and length of int, bigint, smallint, and tinyint in mysql

Blog. csdn. netspring21starticledetails7302.163 recently encountered a variety of numeric types when using the mysql database, including int, bigint, smallint, and tinyint. The difference between int and smallint is confusing. Today, I searched for it on the Internet and found the following content to keep the file for a summary: using the integer number

Http://blog.csdn.net/spring21st/article/details/7307263 recently used mysql database encountered a variety of numeric types, mainly int, bigint, smallint and tinyint. The difference between int and smallint is confusing. Today, I searched for it on the Internet and found the following content to keep the file for a summary: using the integer number

Http://blog.csdn.net/spring21st/article/details/7307263

Recently, mysql Databases have encountered multiple numeric types, including int, bigint, smallint, and tinyint. The difference between int and smallint is confusing. Today, I searched for the following content on the Internet, and made a summary:

Use the exact numeric data type of integer data.

Bigint

Integer Data from-2 ^ 63 (-9223372036854775808) to 2 ^ 63-1 (9223372036854775807) (All numbers ). The storage size is 8 bytes.

P.S.Bigint has a length. The length in the mysql table is only used to display the digits.

Int

Integer Data from-2 ^ 31 (-2,147,483,648) to 2 ^ 31-1 (2,147,483,647) (All numbers ). The storage size is 4 bytes.IntThe SQL-92Integer.

Smallint

Integer Data from-2 ^ 15 (-32,768) to 2 ^ 15-1 (32,767. The storage size is 2 bytes.

Tinyint

Integer Data from 0 to 255. The storage size is 1 byte.

Note

Supported by integerBigintData type. However,BigintUsed in some special cases, when the integer value exceedsIntYou can useBigint. In SQL Server,IntThe data type is the main integer data type.

In the data type priority table,BigintLocated inSmallmoneyAndInt.

Only when the parameter expression isBigintThe function returns the data type.Bigint. SQL Server does not automatically convert other integer data types (Tinyint,SmallintAndInt)Bigint.

Int (M) in integer data type, M indicates the maximum display width. In int (M), the value of M has nothing to do with the storage space occupied by int (M. There is no relationship with the number of digits. int (3), int (4), and int (8) occupy the storage space of 4 btyes on the disk.