The Ultimate Guide to High Availability with MariaDB

INT

Contents

  1. Syntax
  2. Description
  3. Examples
    1. With strict_mode set
    2. SIGNED and UNSIGNED
    3. Out-of-Range
    4. INT ZEROFILL
  4. See Also

Syntax

INT[(M)] [SIGNED | UNSIGNED | ZEROFILL]
INTEGER[(M)] [SIGNED | UNSIGNED | ZEROFILL]

Description

A normal-size integer. When marked UNSIGNED, it ranges from 0 to 4294967295, otherwise its range is -2147483648 to 2147483647 (SIGNED is the default). If a column has been set to ZEROFILL, all values will be prepended by zeros so that the INT value contains a number of M digits. INTEGER is a synonym for INT.

Note: If the ZEROFILL attribute has been specified, the column will automatically become UNSIGNED.

INT4 is a synonym for INT.

For details on the attributes, see Numeric Data Type Overview.

Examples

With strict_mode set

CREATE TABLE ints (a INT,b INT UNSIGNED,c INT ZEROFILL);

INSERT INTO ints VALUES (-10,-10,-10);
ERROR 1264 (22003): Out of range value for column 'b' at row 1

INSERT INTO ints VALUES (-10,10,-10);
ERROR 1264 (22003): Out of range value for column 'c' at row 1

INSERT INTO ints VALUES (-10,10,10);

INSERT INTO ints VALUES (2147483648,2147483648,2147483648);
ERROR 1264 (22003): Out of range value for column 'a' at row 1

INSERT INTO ints VALUES (2147483647,2147483648,2147483648);

SELECT * FROM ints;
+------------+------------+------------+
| a          | b          | c          |
+------------+------------+------------+
|        -10 |         10 | 0000000010 |
| 2147483647 | 2147483648 | 2147483648 |
+------------+------------+------------+

SIGNED and UNSIGNED

The INT data type may be SIGNED (allowing negative values) or UNSIGNED (not allowing negative values).

Example of INT SIGNED (the default):

CREATE TABLE int_signed_example (
   description VARCHAR(20),
   example INT SIGNED
);

INSERT INTO int_signed_example VALUES
   ('Zero', 0),
   ('Forty-Two', 42),
   ('Minimum', -2147483648),
   ('Maximum', 2147483647);

Example of INT UNSIGNED:

CREATE TABLE int_unsigned_example (
   description VARCHAR(20),
   example INT UNSIGNED
);

INSERT INTO int_unsigned_example VALUES
   ('Zero', 0),
   ('Forty-Two', 42),
   ('Minimum', 0),
   ('Maximum', 4294967295);

Out-of-Range

A value is considered "out-of-range" when it is too small or too large to be stored in a data type. When sql_mode=STRICT_TRANS_TABLES (the default) is set, an out-of-range value generates an error. If strict mode is not in effect, the value is rounded to the nearest valid value and a warning is generated (which might be hidden, depending on your warning settings).

An example of non-strict out-of-range behavior:

TRUNCATE int_signed_example;

-- Disable strict mode or the inserts will fail
SET sql_mode=(SELECT REPLACE(@@sql_mode, 'STRICT_TRANS_TABLES', ''));

INSERT INTO int_signed_example VALUES
   ('Underflow', -2147483649),
   ('Overflow', 2147483648);

Warning (sql 1264): Out of range value for column 'example' at row 1
Warning (sql 1264): Out of range value for column 'example' at row 2

SELECT * FROM int_signed_example;

+-------------+-------------+
| description | example     |
+-------------+-------------+
| Underflow   | -2147483648 |
| Overflow    |  2147483647 |
+-------------+-------------+

TRUNCATE int_unsigned_example;

-- Disable strict mode or the inserts will fail
SET sql_mode=(SELECT REPLACE(@@sql_mode, 'STRICT_TRANS_TABLES', ''));

INSERT INTO int_unsigned_example VALUES
   ('Underflow', -1),
   ('Overflow', 4294967296);

Warning (sql 1264): Out of range value for column 'example' at row 1
Warning (sql 1264): Out of range value for column 'example' at row 2

SELECT * FROM int_unsigned_example;

+-------------+------------+
| description | example    |
+-------------+------------+
| Underflow   |          0 |
| Overflow    | 4294967295 |
+-------------+------------+

INT ZEROFILL

A special type of INT UNSIGNED is INT ZEROFILL, which pads out the values with leading zeros in SELECT results. The number of leading zeros are just enough to pad the field out to the length of the type's maximum unsigned value, but the zeros are not included in an expression result or in a UNION SELECT column.

Using INT ZEROFILL works the same way as INT UNSIGNED for most operations except a simple SELECT. For example, with the following test table setup:

CREATE TABLE int_zerofill_example (
   description VARCHAR(20),
   example INT ZEROFILL
);

INSERT INTO int_zerofill_example VALUES
   ('Zero', 0),
   ('Forty-Two', 42),
   ('Minimum', 0),
   ('Maximum', 4294967295);


-- Turn off strict mode or the inserts will fail
SET sql_mode=(SELECT REPLACE(@@sql_mode, 'STRICT_TRANS_TABLES', ''));

INSERT INTO int_zerofill_example VALUES
   ('Underflow', -1),
   ('Overflow', 4294967296);

Warning (sql 1264): Out of range value for column 'example' at row 1
Warning (sql 1264): Out of range value for column 'example' at row 2

The resulting data would look like this:

SELECT *, example + 0 FROM int_zerofill_example;

+-------------+------------+-------------+
| description | example    | example + 0 |
+-------------+------------+-------------+
| Zero        | 0000000000 |           0 |
| Forty-Two   | 0000000042 |          42 |
| Minimum     | 0000000000 |           0 |
| Maximum     | 4294967295 |  4294967295 |
| Underflow   | 0000000000 |           0 |
| Overflow    | 4294967295 |  4294967295 |
+-------------+------------+-------------+

See Also

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