Microsoft KB Archive/922981

= FIX: A System.InvalidCastException exception may occur when you call the OdbcConnection.GetSchema method in the .NET Framework 2.0 =

Article ID: 922981

Article Last Modified on 12/3/2007

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APPLIES TO


 * Microsoft .NET Framework 2.0

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SYMPTOMS
When you call the OdbcConnection.GetSchema method in the Microsoft .NET Framework 2.0, a System.InvalidCastException exception may occur. This problem may occur if the following conditions are true:
 * You call the OdbcConnection.GetSchema method by using a DataTypes parameter value.
 * You use a third-party ODBC driver that is compliant with ODBC version 3.0 or a later version.



CAUSE
The OdbcConnection.GetSchema method calls the SQLGetTypeInfo function in the ODBC API. The SQLGetTypeInfo function returns a result set that contains several columns. Some ODBC drivers may implement a column by using an incorrect SQL data type. For example, some ODBC drivers implement the following columns by using a signed value:
 * CASE_SENSITIVE
 * FIXED_PREC_SCALE
 * UNSIGNED_ATTRIBUTE

These columns should use the SQL_SMALLINT value instead. The SQL_SMALLINT value is an unsigned value. If one of these columns uses a signed value, a System.InvalidCastException exception occurs when Microsoft ADO.NET tries to cast the value to a System.Int32 value.



Hotfix information
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 Microsoft .NET Framework 2.0 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.

Prerequisites
You must have the .NET Framework 2.0 installed to apply this hotfix.

Restart requirement
You do not have to 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.

The .NET Framework 2.0 for 64-bit systems (IA-64)


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
For more 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

