What is a Database?

·       A database is a collection of information.  This information is stored in a very structured manner.  By exploiting this known structure, we can access and modify the information quickly and correctly.

·       In this information age, databases are everywhere:

Þ    When you go to the library and look up a book on their computer, you are accessing the library’s book database.

Þ    When you go on-line and purchase some product, you are accessing the web merchant’s product database.

Þ    Your friendly bank keeps all your financial records on their database.  When you receive your monthly statement, the bank generates a database report.

Þ    When you call to make a doctor appointment, the receptionist looks into their database for available times.

Þ    When you go to your car dealer for repairs, the technician calls up your past work record on the garage database.

Þ    At the grocery store, when the checker scans each product, the price is found in the store’s database, where inventory control is also performed.

Þ    When you are watching a baseball game on television and the announcer tells you that “the batter is hitting .328 against left-handed pitchers whose mother was born in Kentucky on a Tuesday morning,” that useless information is pulled from the team’s database.

·       You can surely think of many more places that databases enter your life.  The idea is that they are everywhere.  And, each database requires some way for a user to interact with the information within.  Such interaction is performed by a database management system (DBMS). 

·       The tasks of a DBMS are really quite simple.  In concept, there are only a few things you can do with a database:

1. View the data
2. Find some data of interest
3. Modify the data
4. Add some data
5. Delete some data

There are many commercial database management systems that perform these tasks.  Programs like Access (a Microsoft product) and Oracle are used world-wide.  In this course, we look at using Visual Basic as a DBMS.

·       Examples where you might use Visual Basic as a DBMS:

Þ    Implementing a new application that requires management of a database

Þ    Connecting to an existing database

Þ    Interacting with a database via the internet

·       In a DBMS, the database may be available locally on your (or the user’s) computer, available on a LAN (local area network) shared by multiple users, or only available on a web server via the Internet.  In this course, we spend most of our time looking at local databases, but access with remote databases is addressed.

·       We will look at databases in more depth in the next chapter.  You will see that databases have their own vocabulary.  Now, let’s take a look at how Visual Basic fits into the database management system.