FIX: SqlDecimal.Round method incorrectly rounds up some decimal values (839423)


The information in this article applies to:

  • Microsoft ADO.NET (included with the .NET Framework 1.1)
  • Microsoft ADO.NET (included with the .NET Framework) 1.0

SYMPTOMS

With certain decimal numbers, the SqlDecimal.Round method incorrectly rounds up instead of down. For example, the following code should display the value 15.7780000, but instead it displays 15.7790000:
SqlDecimal decTest = SqlDecimal.Round(15.7780505m, 3);
Console.WriteLine(decTest);

CAUSE

This is caused by a bug in the rounding algorithm when there is a zero immediately to the right of the last significant digit, and the number to the right of that zero is 5 or higher. The last significant digit is determined by the second argument that is passed to the SqlDecimal.Round method. When you use the code in the "Symptoms" section as an example, 15.7780505 will incorrectly round up to 15.7790000. However, 15.7780405 will correctly round down to 15.7780000.

RESOLUTION

A supported hotfix is now available from Microsoft, but it is only intended to correct the problem that is described in this article. Only apply it to systems that are experiencing this specific problem. This hotfix may receive additional testing. Therefore, if you are not severely affected by this problem, we recommend that you wait for the next service pack that contains this hotfix.

To resolve this problem immediately, contact Microsoft Product Support Services to obtain the hotfix. For a complete list of Microsoft Product Support Services telephone numbers and information about support costs, visit the following Microsoft Web site:

http://support.microsoft.com/contactus/?ws=support

Note In special cases, charges that are ordinarily incurred for support calls may be canceled if a Microsoft Support Professional determines that a specific update will resolve your problem. The usual support costs will apply to additional support questions and issues that do not qualify for the specific update in question. The English version of this hotfix has the file attributes (or later) that are listed in the following table. The dates and times for these files are listed in coordinated universal time (UTC). When you view the file information, it is converted to local time. To find the difference between UTC and local time, use the Time Zone tab in the Date and Time tool in Control Panel. 
   Date         Time   Version            Size    File name
   --------------------------------------------------------------
   26-Mar-2004  23:28  1.1.4322.1017   1,294,336  System.data.dll

WORKAROUND

To work around this problem without applying this fix, use the Math.Round method instead of the SqlDecimal.Round method.

STATUS

Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section of this article.

MORE INFORMATION

For additional information, click the following article number to view the article in the Microsoft Knowledge Base:

824684 Description of the standard terminology that is used to describe Microsoft software updates

Modification Type:MinorLast Reviewed:6/1/2006
Keywords:kbfix kbBug kbHotfixServer kbQFE KB839423 kbAudDeveloper
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