Understanding the Role of ZEROFILL in MySQL INT Datatype

Within the MySQL database system, defining an INT datatype with ZEROFILL provides specific advantages.

Benefit/Usage of ZEROFILL

When applied to an INT datatype, ZEROFILL specifies that the displayed value of the field should be padded with leading zeros up to a defined display width. This ensures consistent field lengths, enhancing readability and improving data alignment.

It's important to note that using ZEROFILL also implies that the field is unsigned, meaning it can only store positive values.

While ZEROFILL alters the display, it does not impact the underlying data storage. The data is not truncated or altered by the use of ZEROFILL and display width.

Example Usage of ZEROFILL

The following code demonstrates the practical application of ZEROFILL:

CREATE TABLE example (
  id INT(8) ZEROFILL NOT NULL,
  value INT(8) NOT NULL
);
INSERT INTO example (id, value) VALUES
(1, 1),
(12, 12),
(123, 123),
(123456789, 123456789);
SELECT id, value FROM example;

Result:

          id           value
00000001               1
00000012              12
00000123             123
123456789 123456789

In this example, the ZEROFILL padding aligns the ID field with a minimum width of 8 characters, making it easier to compare values and identify potential issues.