Visual Basic Q&A

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Entries Tagged ‘application programming interface’

A string that you pass to an unmanaged Win32 API in Visual Studio .NET or in Visual Studio 2005 returns empty

Symptoms
When you pass a String data type variable to a Win32 application programming interface (API) as an out parameter, the string that the Win32 function call returns does not change.
Resolution
This problem occurs because you cannot modify Visual Basic .NET, Visual Basic 2005, and Visual C# strings. By default, you cannot change the String class after the String class is created. For more information about the String class, see the “References” section.

PRB: Error When You Create SQL Server TEMP Tables Using Remote Data Objects (RDO)

Symptoms
When you create a SQL Server local temporary table using the rdoConnection object by calling its .Execute method with default parameters, and then attempt to access the table after the Remote Data Objects (RDO) method has run, you may receive one of the following error messages:

Run-time error ‘40002′: 37000:[Microsoft][ODBC SQL Server Driver][SQL Server] Statement(s)could not be prepared
-or-

Run-time error ‘40002′: S0002:[Microsoft][ODBC SQL Server Driver][SQL Server] Invalid Object Name ‘#<Name of the temporary table>’
Resolution
The creation and use of temporary database tables to facilitate the storage and manipulation of volatile intermediate data is a common programming practice. The default behavior of the SQL Server Open Database Connectivity (ODBC) driver is to create and use temporary stored procedures to run prepared statements. The .Execute method of the rdoConnection object uses the SQLPrepare() and SQLExecute() ODBC application programming interface (API) calls by default to run a SQL statement as a prepared statement. Temporary tables that are created by a stored procedure are automatically dropped when the procedure completes execution. As a result, when you attempt to access a SQL Server temporary table that was created by calling the .Execute method of an rdoConnection object with default parameters, in subsequent statements you receive one of the error messages specified in the “Symptoms” section.