What Does the Number in `int(11)` Actually Represent?

Understanding int(11) vs. int(Anything Else)

When working with integers in database tables, you may encounter variations in the syntax, such as int(11), int(10), or even int(4). What do these numbers represent, and why do they differ?

The integer specified within the parentheses, e.g., 11, is not related to storage requirements or performance. Instead, it defines the display width, which determines how the integer will be presented within the table.

When using the UNSIGNED ZEROFILL option, setting the display width becomes significant. This option right-pads the integer value with zeroes to meet the specified width.

For instance, with INT(4) UNSIGNED ZEROFILL:

0001
0002 
...
0099
...
0999
...
9999
...
10000

Without UNSIGNED ZEROFILL, spaces are used instead of zeroes for padding:

   1
   2 
...
  99
...
 999
...
9999
...
10000

By modifying the display width, the authors of database tutorials aim to control the number of characters displayed within the column for a more compact or readable presentation. In some cases, this can be useful for aligning columns or formatting data to suit specific requirements.

It's important to note that changing the display width does not affect the underlying storage requirements or the range of values that can be stored in the column. The display width merely specifies how the integer will be presented within the table, providing a visual representation that can aid in data management and analysis.

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