IBCPSession::BCPColumns (OLE DB)
Sets the number of fields that are to be bound to the columns in a SQL Server table.
Internally it calls IBCPSession::BCPColFmt to set the default values for field data. These default values are obtained from the SQL Server column information that the provider internally retrieves when the table name is specified through IBCPSession::BCPInit.
This method can be called only after BCPInit has been called with a valid file name.
You should call this method only if you intend to use a user-file format that differs from the default. For more information about a description of the default user-file format, see the BCPInit method.
After calling the BCPColumns method, you must call the BCPColFmt method for each column in the user file to completely define a custom file format.