How to Retrieve Data from the Host File System

Just as you can do with other managed data providers, you can access host data with an implementation of a DataReader object through HostfileCommand.

To retrieve data using a data reader

1. Create an instance of HostFileCommand.

2. Create a DataReader object through a call to HostFileCommand.ExecuteDBDataReader.

   Calling ExecuteDBDataReader retrieves data rows from the data source.

3. Use DBDataReader.Read to obtain a row from the results of the query.

   You can access each column of the returned row by passing the name or ordinal reference of the column to the DBDataReader object. However, for best performance, the DBDataReader object provides a series of methods that enable you to access column values in their native data types (GetDateTime, GetDouble, GetGuid, GetInt32, and so on).

4. Once you are finished with the DBDataReader object, call DBDataReader.Close.

   If your HostFileCommand object contains output parameters or return values, they will not be available until the DBDataReader is closed.

   Note that while DBDataReader is open, the HostFileConnection is in use exclusively by that DBDataReader. You cannot execute any commands for the HostFileConnection, including creating another DBDataReader, until the original DBDataReader is closed.

See Also

Retrieving Information from the Host File System
BizTalk Adapter for Host Files Configuration