1. Task 1
The scenario and table given in the question helps us to create a database system as it
provides all the data we need. The first task is to draw the ER diagram, to draw it the scenario
was clearly understood and the table was fully normalized. Entities are referred as a set of a
data or attributes. The entities from the table must have relation with another entity to form and
understand the table easily. Without the relationship between the entities it’s very difficult to
draw the Er diagram. Er diagram is a conceptual way to explain the database. For normalization
various steps was carried out and at last it was fully normalized and all the entities we need was
obtained from which the ER diagram was drawn. The entities which were obtained are as
follows:
Bijay_Staff
Bijay_Customer
Bijay_Item
Bijay_Supplier
Bijay_Staff_Type
Bijay_Staff_Bijay_Event
Bijay_Event
Bijay_Event_Type
Bijay_Item_Bijay_Event
1) ER DIAGRAM
“An entity-relationship diagram (ERD) is a data modeling technique that graphically
illustrates an information system’s entities and the relationships between those entities.”
(Janssen, 2010). The ER diagram for proposed database system for Dixon’s Parties is
given below.
Figure 1: ER MODEL OF DIXON'S PARTIES
2. 2) Data Dictionary
Data dictionary is also known as metadata (Data about data). It provides
all the required information of the entities. Various information’s like length, key, type, etc of the
entities can be known from the data dictionary. One of the most important parts of an Oracle
database is its data dictionary, which is a read-only set of tables that provides information about
the database. (oracle, 2015)
a) Table name: Bijay_Customer
b) Table name: Bijay_Supplier
c) Table name: Bijay_Item
d) Table name: Bijay_Staff
4. Task 2 – Data and Queries
Before creating table we have to create username and password and grant all privileges
to it using command prompt which will be needed while using Oracle SQL developer.
We will work with the same username and password created in the SQL developer.
Creating Tables:
The tables were created by using Oracle SQL developer by using ‘create’ query in it
and also to check the selection process was carried out.
To create Bijay_Customer table
5. To create Bijay_Supplier table
To create Bijay_Item table
To create Bijay_Event_type table
6. To create Bijay_Staff_type table
To create Bijay_Staff table
7. To create Bijay_Event table
To create Bijay_Staff_Bijay_Event table
To create Bijay_Item_Bijay_Event table
8. Inserting values in table
Then we insert the values in the table which we have created above.
1) Bijay_Customer:
2) Bijay_Supplier
12. To Select the data
For selecting the data we use ‘select’ query and display result as shown below:
Query that selects all the event ordered by a particular customer.
Query that selects the staff and items assigned to an event
13. Querythat selects all customer details for events that require a laptop.
Query that counts all the birthdays that need equipment from Gog’s Sound
and Lights.
Query that shows all the event and their customers that need a waiter.
14. Task 3
Give an assessment of how the work you have done has met the
requirements of Dixon’s Parties.
At last we are able to create the database management system for the Dixon’s Parties.
The scenario provided has table with lots of data duplicity and it was very difficult to
show the relationship between the entities. Also the table was also not normalized and
data integrity is also not maintained. To remove the data duplicity the entities was
normalized by different steps first it was normalized in 1NF then on 2NF and finally in
3NF which removes data duplicity and also help in maintaining the data integrity. From
the normalization we obtain nine tables. By normalization it’s easy to show the relation
between the entities and also the data duplicity was removed. Also there was no
problem while creating the tables and inserting values in it. The relationships between
the entities were also properly maintained. Also the entities have been added wherever
needed. From the normalization process only we are able to draw the ER diagram
easily. The ER diagram was able to describe the database in a conceptual way. Also the
data dictionary for the nine tables which we get from the normalization has been
provided which has all the description of the entity that we required. In the data
dictionary primary key and foreign key for required entities has been assigned.
After assigning the keys we create the tables of Dixon’s Parties by using
oracle SQL Developer. The nine tables were created in it and the values were also
inserted in table by using different queries of SQL Developer. Also keys were assigned
to the entities. To assure that all the queries were correct several times the selection
process was carried out and all the queries were correct too. The data’s of the Dixon’s
Parties were recorded or kept in a table successfully and in a easy way. The table can
be viewed in a various way. The database was able to keep the record of customer,
staff, event, item in a proper way by showing the relation between them. There is various
relation between the entities like one to many, many to one and many to many. The link
between the entities are properly shown and managed. . Moreover, there is control in
data integrity which was properly maintained and data redundancy was also controlled.
In this way all the work we have done has met all the requirements of Dixon’s Parties.
