In this section, I discuss creating and configuring database connections in a site’s data sources. There are a couple of points you should consider at the outset of configuring database connections. These include
• Authentication: The type of authentication used to connect to a database might determine whether you can write data back to the database from SharePoint.
• Data types: As part of configuring a database connection you should consider the data types used in the source database and how they might be interpreted when working with the imported data source in SharePoint Designer 2010. For example, if a field within your external database is configured as a data type of
varbinary(MAX), SharePoint Designer attempts ...