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| Lesson 4
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A relational database analogy | |
| Objective |
Understand the concept of relational databases. | |
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Use an analogy to understand the concept of relational databases.
Relational databases let you use information in the same manner that you think about it. For example, suppose you have an appointment with your attorney and you need to take a file to the office when you go to see her. You probably will make a notation in your calendar that you have the appointment and that you need to take the file with you when you go. What you don't do is make a copy of the file, place it in your calendar, and then take that copy with you. What you're really doing is relating the attorney's appointment with the file you need. 
This is how relational databases work.
When you retrieve the information from the database, you simply say, "I want this piece of information
and those items that relate to it."
For example, with the attorney appointment, your request would be: " Tell me what time the appointment is to meet with Ms. Smith, and give me the file(s) I'll need for the matters we'll be discussing." You just requested the related materials. That's the whole point behind SQL and relational databases. You ask for what you need and let the database do the work and go get it for you. |
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