Visual Basic Q&A

Symptoms
If more than one connection exists in Microsoft Visual Studio .NET Server Explorer, and if you cannot see Server Explorer in Visual Studio .NET, you may receive the following error message when you click Fill Dataset to preview the data in the Data Adapter Preview window:

SqlDataAdapterName. The data adapter could not return the data from the data source.
The connection string is invalid.Alternatively, when you right-click DataAdapter and then click Generate Dataset, you may receive the following error message:

Retrieving the schema for SqlDataAdapter1 failed.
The connection string is invalid.
Resolution
Connection Manager manages the Microsoft SQL Server connections in Visual Studio .NET. When you click Fill Dataset or Generate Dataset, a Connection object is built and then added to the Connection Manager list of Connection objects. Connection Manager finds the Connection in its list and then prepares to return the Connection with the display name of the Connection. To return the display name, Connection Manager incorrectly opens Server Explorer and then looks for a connection in Server Explorer. Connection Manager generates an error because the connection does not exist in Server Explorer.

Symptoms
The number of connections opened on SQL Server increases indefinitely if a Microsoft Data Access Objects (DAO) recordset is opened and closed repeatedly when you use DAO version 3.6. This does not happen if you use DAO version 3.51. You may see this behavior if you use sqlpassthrough in which the connection string is specified in the OpenDatabase statement.
Resolution
Use a Querydef to create the connection instead of creating the connection in the OpenDatabase statement.