normalization

[amal2004]

hii
i have these unnormalized data..i wanna normalized these up to 3NF.
I tried 1st NF..but im not sure whether its correct ..if anyone can pls help me.

HIREINFO (Machine_ID, Hire_customer_name, Hire_customer_address, Date_of_hire, Days_hire, Price_of_hire_per_day, Hire_customer_category, Category_description, Hire_category_discount_percentage)

1st NF-

Customer_Details ([Customer_ID, Machine_ID]pk, Hire_customer_name, Hire_customer_address, Hire_customer_category, Category_description, Hire_category_discount_percentage)

Hire_Details (Machine_ID[pk], Date_of_hire, Days_hire, Price_of_hire_per_day,)

[andreasblixt]

You've got machine, customer, category and hire occasion. The machine information isn't actually included (it is only referenced), so I haven't listed it as a table below:

Customers
 Customer_ID [PK]
 Name
 Address

Hire_occasions
 Hire_occasion_ID [PK]
 Category_ID [FK]
 Customer_ID [FK]
 Machine_ID [FK]
 Date_of_hire
 Days_hire
 Price_of_hire_per_day

Categories
 Category_ID [PK]
 Name
 Description
 Discount_percentage

The "Hire_customer_category" confuses me a bit - I assumed it's a category for the hire, but it almost sounds as if it's a category for the customer. If that's the case, move Category_ID in Hire_occasions to Customers.

If the Price_of_hire_per_day is determined by the category, you could copy the field to Categories. I wouldn't keep it only in Categories however, as you wouldn't want to risk it changing for a category and tainting your historical data (the price would suddenly change for hires that have already occurred.)