What is the size of column of int(11) in mysql in bytes?

What is the size of column of int(11) in mysql in bytes?

And Maximum value that can be stored in this columns?

 Answers

An INT will always be 4 bytes no matter what length is specified.

• TINYINT = 1 byte (8 bit)
• SMALLINT = 2 bytes (16 bit)
• MEDIUMINT = 3 bytes (24 bit)
• INT = 4 bytes (32 bit)
• BIGINT = 8 bytes (64 bit).

The length just specifies how many characters to display when selecting data with the mysql command line client.

... and the maximum value will be 2147483647 (Signed) or 4294967295 (Unsigned)

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INT(somenumber) will make difference only in term of display, that is to show in the number in 'somenumber' digits, and not restricted only to 11. You pair it using ZEROFILL, which will prepend the zeros until it matches your length

Note that the value stored in database is not affected, any calculation will still behave as it is.

Remarks :

• if the value has less digit than 'somenumber', ZEROFILL will prepend zeros.

  INT(5) ZEROFILL with the stored value of 32 will show 00032
  INT(5) with the stored value of 32 will show 32
  INT with the stored value of 32 will show 32

• if the value has more digit than 'somenumber', the stored value will be shown.

  INT(3) ZEROFILL with the stored value of 250000 will show 250000
  INT(3) with the stored value of 250000 will show 250000
  INT with the stored value of 250000 will show 250000

The similar applies to BIGINT, MEDIUMINT, SMALLINT, and TINYINT as well.

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As others have said, the minumum/maximum values the column can store and how much storage it takes in bytes is only defined by the type, not the length.

A lot of these answers are saying that the (11) part only affects the display width which isn't exactly true, but mostly.

A definition of int(2) with no zerofill specified will:

• still accept a value of 100
• still display a value of 100 when output (not 0 or 00)
• the display width will be the width of the largest value being output from the select query.

The only thing the (2) will do is if zerofill is also specified:

• a value of 1 will be shown 01.
• When displaying values, the column will always have a width of the maximum possible value the column could take which is 10 digits for an integer, instead of the miniumum width required to display the largest value that column needs to show for in that specific select query, which could be much smaller.
• The column can still take, and show a value exceeding the length, but these values will not be prefixed with 0s.

The best way to see all the nuances is to run:

CREATE TABLE `mytable` (
    `id` int(11) NOT NULL AUTO_INCREMENT,
    `int1` int(10) NOT NULL,
    `int2` int(3) NOT NULL,
    `zerofill1` int(10) ZEROFILL NOT NULL,
    `zerofill2` int(3) ZEROFILL NOT NULL,
    PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

INSERT INTO `mytable` 
(`int1`, `int2`, `zerofill1`, `zerofill2`) 
VALUES
(10000, 10000, 10000, 10000),
(100, 100, 100, 100);

select * from mytable;

which will output:

+----+-------+-------+------------+-----------+
| id | int1  | int2  | zerofill1  | zerofill2 |
+----+-------+-------+------------+-----------+
|  1 | 10000 | 10000 | 0000010000 |     10000 |
|  2 |   100 |   100 | 0000000100 |       100 |
+----+-------+-------+------------+-----------+

Notice how int1 column has a much smaller display width than zerofill2 even though the length is larger.

This answer is tested against MySQL 5.7.12 for Linux and may or may not vary for other implementations.

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Though this answer is unlikely to be seen, I think the following clarification is worth making:

• the (n) behind an integer data type in MySQL is specifying the display width
• the display width does NOT limit the length of the number returned from a query
• the display width DOES limit the number of zeroes filled for a zero filled column so the total number matches the display width (so long as the actual number does not exceed the display width, in which case the number is shown as is)
• the display width is also meant as a useful tool for developers to know what length the value should be padded to

A BIT OF DETAIL
the display width is, apparently, intended to provide some metadata about how many zeros to display in a zero filled number.
It does NOT actually limit the length of a number returned from a query if that number goes above the display width specified.
To know what length/width is actually allowed for an integer data type in MySQL see the list & link: (types: TINYINT, SMALLINT, MEDIUMINT, INT, BIGINT);
So having said the above, you can expect the display width to have no affect on the results from a standard query, unless the columns are specified as ZEROFILL columns
OR 
in the case the data is being pulled into an application & that application is collecting the display width to use for some other sort of padding.

Primary Reference: https://blogs.oracle.com/jsmyth/entry/what_does_the_11_mean

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I think max value of int(11) is 4294967295