Tasks 1 - 4
TASK 1 State the main aims of normalisation:
- One aim of normalisation is to get rid of anomalies when you add, delete or amend records. This is because adding and deleting records and amending data in records can result in data inconsistencies.
- The other main aim of normalisation is …
TASK 2 Normalise a bank's customer database! A typical example record is shown below.
Use exactly the same method as you have just seen. Start at 'Step 0 - Set up the Analysis Table'. To make life easier for ourselves at this point, we will assume that every account number is unique - you cannot have two account numbers that are the same, even if they are different types of account or belong to different customers. This means that if you want a balance, you only need the account number. You do not need the customer’s ID. The balance depends just upon the account number. (This will help you when you normalise the database from 1NF to 2NF.)
TASK 3 Normalise a student-course database. A typical record is shown below.
TASK 4 A database is to be kept that records all the parts that make up a particular model of digital camera.
Following an analysis of the problem, it is found that these details are to be kept about each individual camera:
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- The camera model (which is unique for every camera).
- The date the camera was released for sale.
For each camera, the following details about every part needed to build it will be kept:
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- A part number.
- A part name.
- The ID of the manufacturer of the part.
- The name of the manufacturer of the part.
- Your job is to produce a normalised design for the database. Use the table below.
(HINT: If you are not sure how to start, why not sketch out a typical record card for one camera and then fill it in with some made-up data. It will help you visualise the problem. Use this table to structure your answer.)