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This article goes out to all MFC programmers who wish to improve their applications performance and those who have tried calling stored procedures and failed. Your first question may be, Why use stored procedures when I can just say, rs.Open( CRecordset::snapshot, “Select * from Clients where account_number = ‘1234567’”);. Well theres 2 answers that I […]

ActiveX Data Objects (ADO) enables you to write a client application to access and manipulate data in a database server through a provider. ADO’s primary benefits are ease of use, high speed, low memory overhead, and a small disk footprint. This sample project is for ADODB, an implementation of ADO optimized for use with Microsoft […]

The class CRecordset provides a well documented way to call stored procedures that return records. If a stored procedure does not return records and has no output parameters, the CDatabase member ExecuteSQL can be used to call it. On the other hand, the documentation explicitly states that the MFC classes do not support for calling […]

. This article will explain how to print mailing labels using an ODBC database, OnPrint, and OnDraw. I used VC++ version 5 with service patch 2 installed, but it should work with any version of VC++. To get my mailing labels printed I first used Crystal Reports. While this worked, I was not happy with […]

All the books that I4ve read have the official chapter ” Database programming”, a little chapter in which there is the typical example of: Create a new project, with App wizard select the option use database and select what database will you use… Ok, I begin my application, and one month later I realize “mmm…., […]

Sometimes it is useful to know if the computer running your software has the DAO Jet Engine version 3.5 installed. You need this engine when you work with MFC DAO objects. I needed to know if DAO 3.5 was there while writing my own setup program for a piece of work which used the CDaoXYZ […]

1. MS Access drivers (upto and including Access 97) are not thread safe. 2. Always make user your DoFieldExchange order is the same as the order of fields in the DB table. The class wizzard will occasionally change the order at you. 3. Don’t use 16-bit Ints in your database. Only use Bytes or Longs […]

When you derive a class from CRecordset, the default maximum length assigned by the AppWizard for a string or array during a transfer is 255. A “Data Truncated” error is displayed whenever you attempt to transfer records with fields bigger than that. To solve the problem, specify the length required as the fourth parameter of […]

This sample in this article was created using VC 5.0. The necessary .h and .lib files are present in the zip. To create a DSN at run time you could use the SQLConfigDataSource API. Internally this information is stored in the registry. The syntax is attached below SQLConfigDataSource(NULL,ODBC_ADD_DSN,”Microsoft Access Driver (*.mdb)”,”DSN=TestDBDBQ=D:\Database\Friends.mdbDEFAULTDIR=D:\DATABASE”); The problem is that […]

This example demonstrates how to store a “Paint Brush” image in a Access DB. In my code I have created a CDaoRecordset derived class for handling and reading the binary data. Class Wizard binds a CLongBinary to the Ole Object field when creating the recordset. CLongBinary is difficult to manage, so in the recordset, that […]

Overview This article tries to explain the class library QueryDef intended to be used instead of the classic MFC class CRecordset. CRecordset is a great class with one single exception. You have to generate/write too much code. In a project I was involved there were over 700 recordsets defined. Soon working with CRecordset became a […]

of . This development of this source code was partially sponsored by Dundas Software, and is also used to implement stacked docking dialog bars in these Dundas Software’s MFC components – Ultimate Diagram and the HyperView scriptable forms environment. Features Resizable control bar, that can be resized both when docked and when floating. Multiple sizing […]