rsvarcol.cpp

clips专家系统内核打包类,很有参考性.

// rsvarcol.cpp : implementation file
//
//******************************************************************
// PROJECT NAME:	SQLPRC                                         
// MODULE NAME:		RSVARCOL.CPP                                     
// AUTHOR:			Phillip N. Jacobs
// DESCRIPTION:		Variable-column recordset class implementation
/*
	CVarRecordset is derived from CRecordset and is implemented so
	that you can either derive your own classes from it (for
	example, if you want to bind parameters) or create CVarRecordset
	objects and use it as is.
	
	I implemented the code to determine the number of result columns
	and their attributes in an override of PreBindFields because
	this only needs to be done once.  This means that if you derive
	your own class from CVarRecordset and you want to override
	PreBindFields you MUST call CVarRecordset::PreBindFields
	function from within your override.

	!!!IMPORTANT!!!	
	You MUST call the Open function with the first parameter
	(nOpenType) equal to CRecordset::forwardOnly.
	
	CVarRecordset supports all the SQL statements that CRecordset
	does except for table names.  For example, if you had a
	CRecordset with an SQL statement of "TableName" you would need
	to change it to "SELECT * FROM TableName" in order to use a
	CVarRecordset.  This is because the MFC code requires that at 
	least one result field be bound if plain table names are used.
	Keep in mind that MFC enforces a strict syntax for stored
	procedures which requires that the SQL statement be enclosed in
	curly braces and that the 揷all