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ADO Fundamentals

 

Overview

 

Introduction

Microsoft Windows was created to solve various kinds of computer problems. Text or word processing was taken care of easily as it can be performed using WordPad, an application that ships with every installation of the operating system. All regular calculations were also taken care of as can be verified in Calculator, an application that also ships with MS Window. Basic drawing and graphics can be performed using Paint, another application that is installed with MS Windows.

To support databases in MS Windows, Microsoft created a library called ActiveX Data Objects or ADO. ADO was meant to create, administer, and manipulate databases. To use ADO, you had to first create a database using an application such as Microsoft Access or by other related means. Because this only partly solved the problem, and because this almost restricted people to use Microsoft Access, there was need for additional solutions. Among the limitations of ADO, there was security and even the ability to create a database without necessarily using a product from Microsoft. To address these issues, Microsoft created an additional library called 
Microsoft ActiveX Data Objects Extensions for Data Definition Language and Security, abbreviated ADOX. Nowadays, Microsoft has made free everything you need to create, manage, and even distribute databases (in fact, at this time, except for the operating systems,  Microsoft has developed various libraries and compilers and made them completely free so that you can create any type of application without spending money: you only need time to use them).

 

Using ADO

Although treated as one entity, Microsoft ActiveX Data Object is really many libraries grouped under one name. For the rest of our lessons, ADO will be used to refer to all the technologies we need to create and administer our databases. We will point the differences only when needed.

ADO is only a library, that is, a series of files that provide "drivers" and documentation to perform a task. In order to use ADO, you need a programming or development environment in which you can write code. The environment you use should/must also be able to "understand" your code, analyze it and produce a result. This is not an anomaly of ADO. All libraries work like that. There are many environments you can use with ADO. Some of them are Microsoft Internet Explorer (using scripting languages such as VBScript or JavaScript), Borland Delphi, Microsoft Visual C++, Visual InterDev, Borland C++ Builder, Microsoft Visual Studio. NET, just to name a few.
Author Note When writing the exercises on this site, we had to decide and choose among various available options, unfortunately. Different programming environments offer different advantages and disadvantages. On this site, we will create all of our databases using Microsoft Visual Basic 6. We chose it because at the time of this writing, we found out that many people are still using it. Of course, Microsoft Access would offer the same flexibility but we preferred this because MS Access is already a complete database environment in its own right.

In order to follow the lessons on this site, you are supposed to have some knowledge of Microsoft Visual Basic as it is the main language of ADO. The topics you are:

  • Variables
  • Procedures and Functions
  • Objects and Methods of Objects
  • Conditional Statements

It would be a big waste of time to try to teach both MSVB (which is a language or a programming environment) and ADO (which is a library).

 
 

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