When constructing a database, the designer must know what type of relationship exist between records in different data sets, such as ‘one to one’, ‘one to many’ and ‘many to many’. Choose only one type and give an example of this relationship.
+3
A:
I'm not going to give you outright answers since it's homework, but I will help.
Think about it. Seriously. In what real-world situations would you find each of those relationships between objects?
One-to-many is easy. Think of something that you build one of, but is composed of many smaller parts. That's just about every single thing you can buy from a retail outlet. It's also a model for the normal corporate hierarchy in a company unless you have the dubious distinction of having to report to more than one boss.
Many to many is also relatively easy. Unless you're a social recluse, you will almost certainly consider yourself to have multiple friends as well as being a friend to more than one person. A second possibility is to think about shared rental properties and how they would fit this bill.
For one to one, consider what you must have one, and exactly one, of (not zero, not two or more). That's a little trickier since most things that come to mind (job, wife in a non-polygamous society and so on) allow you to have zero, which is not one to one.
Think in terms of governmental records for tax or health, for example.
paxdiablo
2010-10-10 06:51:54
@paxdiablo - +1 just for the comment about "distinction of having to report to more than one boss" - dubious is right!!! Been there way too often, i am afraid!! Price to pay for working in a "flat" organization! :-)
InSane
2010-10-10 07:24:58
A:
Wow. All you need to do is pick one of those three types and give an example? If you can't do that, consider a different major. Come on, think of two things in your daily life that have any relationship of any kind to each other and think of how they are related. How do students relate to classes for instance...
Jason Goemaat
2010-10-10 06:58:24