MySQL Bugs: #51238: DESC documentation issue going from 5.0 to 5.1 manual versions

Bug #51238	DESC documentation issue going from 5.0 to 5.1 manual versions
Submitted:	17 Feb 2010 11:29	Modified:	18 Feb 2010 16:36
Reporter:	Tobias Asplund	Email Updates:
Status:	Closed	Impact on me:	None
Category:	MySQL Server: Documentation	Severity:	S3 (Non-critical)
Version:		OS:	Any
Assigned to:	Paul DuBois	CPU Architecture:	Any

Description:
12:18:22 < flupps> http://dev.mysql.com/doc/refman/5.1/en/show-columns.html
12:18:52 < flupps> "If Key is UNI, the column is the first column of a unique-valued index that cannot contain NULL values. "
12:22:57 < flupps> +-------+---------+------+-----+---------+-------+
12:22:57 < flupps> | Field | Type    | Null | Key | Default | Extra |
12:22:57 < flupps> +-------+---------+------+-----+---------+-------+
12:22:57 < flupps> | a     | int(11) | YES  | UNI | NULL    |       |
12:23:02 < flupps> Since I can get this to show
12:23:43 < flupps> in the 5.0 manual this text explains it:
12:23:45 < flupps> "Before MySQL 5.0.11, if the column allows NULL values, the Key value can be MUL even when a single-column UNIQUE index is used. 
                   The rationale was that multiple rows in a UNIQUE index can hold a NULL value if the column is not declared NOT NULL. As of MySQL 
                   5.0.11, the display is UNI rather than MUL  regardless of whether the column allows NULL; you can see from the Null field whether 
                   or not the column can contain NULL. "
12:23:50 < flupps> But this text is not present in the 5.1 manual
12:24:38 < stefan> Maybe because it doesn't apply to MySQL 5.1? :-)
12:24:52 < flupps> Right, but the statement it corrects wasn't updated for 5.1 ;)
12:25:14 < stefan> Ah, I see!
12:25:21 < stefan> Can you file this as a docs bug?
12:25:24 < flupps> Will do
12:25:31 < stefan> You may assign it to Paul

How to repeat:
CREATE TABLE t1 ( a INT NULL UNIQUE ); DESC t1;

Thank you for the bug report.

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.