Thursday, August 25, 2005

IColumnsRowset

DesktopSqlCe seems on time to be launched in September. After clearing a lot of hurdles, such as command parameters and direct table seeks, I started to implement the ADO .NET data provider on top of the lower-level classes. A data provider is not a small body of code to write, but you can find help in lots of places, especially in MSDN where templates for all the major classes are provided with detailed explanations. Quite conveniently, the MSDN writers skip some of the trickiest implementations and you can get a bit lost.

Such was the case when I started to implement SqlCeDataReader.GetSchemaTable. This one was a bitch to do. One of the best clues I actually got from the MSDN documentation:

The GetSchemaTable method maps to the OLE DB IColumnsRowset::GetColumnsRowset method (...)

It's not enough, but it's a big step forward. After implementing this using the Consumer Templates, I deceided to write a small article on this subject:
Using IColumnsRowset with the ATL OLE DB Consumer Templates

Enjoy!

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