MySQL Bugs: #10083: round(x,y) doesn't work, when x is integer and y

Bug #10083	round(x,y) doesn't work, when x is integer and y > 0
Submitted:	22 Apr 2005 2:47	Modified:	3 May 2007 2:10
Reporter:	Ronald Weiss	Email Updates:
Status:	Closed	Impact on me:	None
Category:	MySQL Server	Severity:	S3 (Non-critical)
Version:	5.0.4	OS:	Windows (winXP)
Assigned to:	Alexey Botchkov	CPU Architecture:	Any

Description:
The synopsis is clear enough I think.
SELECT ROUND(150,2) returns "150".
I think it should return "150.00" shouldn't it?

I tried in on a 3.23 server, there it is ok.

How to repeat:
SELECT ROUND(150,2)

Reproduced w/5.0.5 from bk.

This problem doesn't happen in 4.1

A patch for this bug has been committed. After review, it may
be pushed to the relevant source trees for release in the next
version. You can access the patch from:

  http://lists.mysql.com/internals/25807

Thank you for your bug report. This issue has been committed to our
source repository of that product and will be incorporated into the
next release.

If necessary, you can access the source repository and build the latest
available version, including the bugfix, yourself. More information 
about accessing the source trees is available at
    http://www.mysql.com/doc/en/Installing_source_tree.html

Pushed into 5.1.18-beta

Pushed into 5.0.42

For docs team:  I'm not sure if this requires amending the documentation; the fix for this bug (bug #10083) was reverted as part of the fix for bug #24912.  See changeset comments on that bug for details.

It was determined that this bug should have been classified as "Not a Bug", and that ROUND(<integer type>, <positive value>) should still return an integer type.  See the manual for more details on ROUND() behavior and return type.

I'll add an example to the 5.0/5.1 manuals to illustrate
what happens for integer and non-integer values.
The manual does indicate already that the return type
is the same as the argument type.

Example:

mysql> SELECT ROUND(150.000,2), ROUND(150,2);
+------------------+--------------+
| ROUND(150.000,2) | ROUND(150,2) |
+------------------+--------------+
|           150.00 |          150 |
+------------------+--------------+