One of the first tasks I encountered when I started working with Managed C++ and ADO.NET was that of reading image data from a SQL Server database and then either saving or displaying the images. As an example, the standard SQL Server Northwind database has a table (Employees) that includes a Binary Large Object (BLOB) column that contains the image data for each employee. This article first lists the steps for reading this data using the .NET DataReader class. It then presents a generic function for reading an image from a SQL Server database and writing that data to a disk file.
If you wish to learn more about ADO.NET and the classes presented here, my book Extending MFC Applications with the .NET Framework has three chapters devoted to ADO.NET, including such advanced subjects as disconnected data, working with hierarchical data, and dealing with issues of concurrency.
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