MySQL Bugs: #33402: ROUND with decimal and non-constant cannot round to 0 decimal places

Bug #33402	ROUND with decimal and non-constant cannot round to 0 decimal places
Submitted:	20 Dec 2007 13:41	Modified:	21 Dec 2007 16:17
Reporter:	Martin Hansson	Email Updates:
Status:	Duplicate	Impact on me:	None
Category:	MySQL Server: Optimizer	Severity:	S3 (Non-critical)
Version:	5.0, 5.1, 6.0	OS:	Any
Assigned to:	Assigned Account	CPU Architecture:	Any

Description:
ROUND(X, D) rounds but does not change number of decimal places if D = 0 and D is not a constant. 

How to repeat:
CREATE TABLE t1 ( a DECIMAL(5, 4), b INT );
INSERT INTO t1 VALUES (1.2345, 0), (1.2345, 1);
SELECT a, b, ROUND(a, b) FROM t1;
/*
+--------+------+-------------+
| a      | b    | ROUND(a, b) |
+--------+------+-------------+
| 1.2345 |    0 |      1.0000 |
| 1.2345 |    1 |         1.2 |
+--------+------+-------------+
*/

Suggested fix:
Patch will follow shortly ;-)

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/commits/40276

ChangeSet@1.2546, 2007-12-20 16:31:19+01:00, mhansson@linux-st28.site +3 -0
  Bug #33402: ROUND with decimal and non-constant cannot
  round to 0 decimal places
  
  The ROUND( X, D ) function did not work if X was DECIMAL andd D was a 
  non-constant equal to 0.
  Fixed by including 0 in the range of valid values for D.

This bug will be fixed as part of the fix for bug#33143

Pushed into 6.0.5-alpha

Pushed into 5.1.24-rc

Pushed into 5.0.56