WGU C170 Objective Assessment – Edward M Burke
First Normal Form – 1 Table
I gleaned this table from the unstructured data contained within the order
form. I made sure not to have any redundant groups, and each column in the
table will contain atomic values. Donut ID, Donut Name, Donut Quantity, Unit
Price, and Donut Description are an example of a repeating group. As I
mentioned earlier, in order to achieve first normal form, we must eliminate
repeating groups. This requires the use of a composite key made up of Donut
Order ID and Donut ID.
Second Normal Form – 3 Tables
In order to achieve second normal form we need to split the first
table into three separate tables so that all non-key attributes are
functionally dependent on the entire primary key. I took the
attributes that are partially dependent on the primary key, and
placed them into separate relations. Donut Name, Donut
Description, and Unit Price depend only on Donut Order ID. Donut
Quantity and Item Total depend on both Donut Order ID and Donut
ID.
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Third Normal Form – 4 Tables
In order to achieve third normal form we need to eliminate any transitive dependency, meaning an attribute depends on
another attribute that is not the primary key. For example, looking at our second normal form tables, Customer Last
Name is dependent on Donut Order ID. (Each Donut Order ID has only one Customer Last Name value associated with it)
To transform into third normal form we simply move any transitively dependent attributes to their own relation where
they depend on only the primary key.
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