MySQL Bugs: #27301: space padding to display width does not occur

Bug #27301	space padding to display width does not occur
Submitted:	20 Mar 2007 19:33	Modified:	29 Oct 2008 20:23
Reporter:	Scott Noyes (Basic Quality Contributor)	Email Updates:
Status:	Closed
Category:	Server: Docs	Severity:	S3 (Non-critical)
Version:	all	OS:	Microsoft Windows (Windows, Linux)
Assigned to:	Paul DuBois	Target Version:
Tags:	qc
Triage:	Triaged: D4 (Minor) / R2 (Low) / E2 (Low)

Description:
http://dev.mysql.com/doc/refman/5.0/en/numeric-types.html says:

"Another extension is supported by MySQL for optionally specifying the display width of
integer data types in parentheses following the base keyword for the type (for example,
INT(4)). This optional display width is used to display integer values having a width
less than the width specified for the column by left-padding them with spaces."

No space padding occurs. If you specify zerofill, then zero padding occurs as documented.

How to repeat:
mysql> CREATE TABLE test (id bigint(10));
Query OK, 0 rows affected (0.05 sec)

mysql> INSERT INTO test VALUES (1);
Query OK, 1 row affected (0.00 sec)

mysql> SELECT * FROM test; -- Should show 9 spaces before the 1
+------+
| id   |
+------+
|    1 |
+------+
1 row in set (0.00 sec)

mysql> ALTER TABLE test MODIFY COLUMN id bigint(10) zerofill;
Query OK, 1 row affected (0.03 sec)
Records: 1  Duplicates: 0  Warnings: 0

mysql> SELECT * FROM test; -- Works as expected
+------------+
| id         |
+------------+
| 0000000001 |
+------------+
1 row in set (0.00 sec)

Suggested fix:
Left pad with spaces as documentation indicates, or alter manual to reflect current
behavior, which is probably what everyone expects anyway.

Thank you for the report.

Verified as described.

triage: correcting tag from SR51MRU to CHECKED as D=4

Thank you for your bug report. This issue has been addressed in the documentation. The
updated documentation will appear on our website shortly, and will be included in the
next release of the relevant products.

The width information *is* present in result set metadata, but need not be used by the
application. I've changed the paragraph in question as follows:

Another extension is supported by MySQL for optionally specifying the
display width of integer data types in parentheses following the base
keyword for the type (for example, INT(4)). This optional display 
width may be used by applications to display integer values having a
width less than the width specified for the column by left-padding 
them with spaces. (That is, this width is present in the metadata
returned with result sets. Whether it is used or not is up to the
application.)