CIS 209 Week 3 discussion

.docx

School

Bellevue University *

*We aren’t endorsed by this school

Course

209

Subject

Information Systems

Date

Apr 3, 2024

Type

docx

Pages

Uploaded by UltraSteelBarracuda36

For me it was a little hard to get a good grasp around how these concepts worked. I made use of this website here to help me better understand what was going on. Yes, I also watched the videos provided and those helped a lot too. First Normal Form First normal form is straight forward and simple to understand. You need to ensure that your table (database) is holding a single value in each column and that they are the same kind of data. Thirdly, each column should have a unique name like last_name and first_name . Finally, the order in which the data is presented does not matter. These are the four basic rules for 1NF. Another good point to make is that these values cannot be broken down into any smaller values (Kozubek, n.d.). This is something we see happening in 2NF and 3NF. Second Normal Form In second normal form , we must make sure the table is in first normal form and that, “no non-prime attributes are dependent on a subset of the candidate key(s)” (Kozubek, n.d.). For example, below you can see that supplier country and supplier share dependency. Supplier is a candidate key and so this is now a problem. (Kozubek, n.d.) How do we fix this? Well, we need to separate “supplier country” into it’s own table. Now, the table should look something like this.

(Kozubek, n.d.) We still have our part and supplier, but now the origin of the supplier is contained in a separate table. Quantity stays in this table because it is dependent on both part and supplier. Below is the other table for the country of origin. (Kozubek, n.d.) Third Normal Form With Third Normal Form, it requires that the table meets 2NF requirements and we can see that it is similar to 2NF practices. Essentially, all non-prime attributes must depend entirely on the candidate key (Kozubek, n.d.). I believe this is best explained through showing data set tables. So here is another great example of how this is put into practice. If you look at the screenshot below you will see that Course and year are the candidate keys for this table. Notice that teacher depends on the two candidate keys while the DOB field depends on teacher. This is an incorrect aspect of this table, so now lets fix this.

Your preview ends here

Eager to read complete document? Join bartleby learn and gain access to the full version

Access to all documents
Unlimited textbook solutions
24/7 expert homework help