Microsoft KB Archive/940932

= FIX: The System.Data.Index.CompareRecords method generates a System.NullReferenceException exception when you try to use code to modify a record in a data table in a .NET Framework 2.0-based application =

Article ID: 940932

Article Last Modified on 12/3/2007

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APPLIES TO


 * Microsoft .NET Framework 2.0

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SYMPTOMS
Consider the following scenario. In a Microsoft .NET Framework 2.0-based application, you bind the application to a data table. Next, you remove a column from the data table. Then, you try to use code to modify a record in this data table. In this scenario, the System.Data.Index.CompareRecords method generates a System.NullReferenceException exception.

This problem occurs if one of the following conditions is true:
 * You remove a primary key from the data table.
 * You remove a constraint collection from the data table.
 * The AllowDBNull property for a column is set to &quot;false,&quot; and you remove this column.
 * The Unique property for a column is set to &quot;true,&quot; and you remove this column.



CAUSE
This problem occurs because internal indexes reference the column that has been removed.



Hotfix information
A supported hotfix is now available from Microsoft. However, it is intended to correct only the problem that is described in this article. Apply it only 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 .NET Framework 2.0 service pack that contains this hotfix.

To resolve this problem immediately, contact Microsoft Customer Support Services to obtain the hotfix. For a complete list of Microsoft Customer 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.

Prerequisites
You must install hotfix 916002 before you install this hotfix. For more information, click the following article number to view the article in the Microsoft Knowledge Base:

916002 FIX: Error message when you try to use the SqlClient class in an ADO.NET 2.0-based application to connect to an instance of SQL Server 2005: &quot;New request is not allowed to start because it should come with valid transaction descriptor&quot;

Restart requirement
You must restart the computer after you apply this hotfix.

Hotfix replacement information
This hotfix does not replace any other hotfixes.

File information
The English version of this hotfix has the file attributes (or later file attributes) 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 item in Control Panel.



WORKAROUND
To work around this problem, create a new data table. Or, use the DataTable.Reset method. This lets you avoid schema changes such as the removal of columns or the removal of a primary key.



STATUS
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the &quot;Applies to&quot; section.



MORE INFORMATION
After you apply this hotfix, you cannot remove a column when a DataView.RowFilter property or a DataView.Sort property references that column.

For more information about the System.NullReferenceException exception, visit the following Microsoft Web site:

http://msdn2.microsoft.com/en-us/library/system.nullreferenceexception(vs.80).aspx

For more information about software update terminology, 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



Call stack information
07d0e4b8 09195ccd System.Data.Index.CompareRecords(Int32, Int32) 07d0e4d8 09195c7a System.Data.Index+IndexTree.CompareNode(Int32, Int32) 07d0e4e4 0ff93c0e System.Data.RBTree`1System.Int32, mscorlib.SearchSubTree(Int32, Int32) 07d0e4fc 0ff940e8 System.Data.RBTree`1System.Int32, mscorlib.GetNodeByKey(Int32) 07d0e514 0ff93ee9 System.Data.Index.RecordStateChanged(Int32, System.Data.DataViewRowState, System.Data.DataViewRowState, Int32, System.Data.DataViewRowState, System.Data.DataViewRowState) 07d0e548 09193e97 System.Data.DataTable.RecordStateChanged(Int32, System.Data.DataViewRowState, System.Data.DataViewRowState, Int32, System.Data.DataViewRowState, System.Data.DataViewRowState) 07d0e598 09191fb7 System.Data.DataTable.SetNewRecordWorker(System.Data.DataRow, Int32, System.Data.DataRowAction, Boolean, Int32, Boolean, System.Exception ByRef) 07d0e648 0ff93e29 System.Data.DataTable.SetNewRecord(System.Data.DataRow, Int32, System.Data.DataRowAction, Boolean, Boolean) 07d0e664 09191485 System.Data.DataRow.EndEdit 07d0e690 0955c905 System.Data.DataRow.set_Item(System.Data.DataColumn, System.Object) 07d0e6cc 0ff9e55a System.Data.DataRow.set_Item(Int32, System.Object)

Keywords: kbfix kbqfe kbpubtypekc kbexpertiseadvanced kbhotfixserver KB940932

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