Relational Database Design using Crow's Foot Notation

Desklib provides solved assignments and past papers to help students succeed.

Contents
Introduction......................................................................................................................................2
1. Dependency diagram:...............................................................................................................2
2. Multivalued dependency..........................................................................................................2
Single dependency.......................................................................................................................3
3. 3NF structure dependencies.....................................................................................................3
Employee table............................................................................................................................3
Professor information table..........................................................................................................3
Department table..........................................................................................................................3
4. Crow Foot notation diagram.....................................................................................................3
Conclusion.......................................................................................................................................4
References........................................................................................................................................5

Introduction
To remove the flaws and issues from the database, the process of normalization is used. It is
necessary to remove the issues because it can create problems which adding, deleting or
modifying the database. This is also helpful to eliminate the redundancy of data. The dependency
of the data is used to assure the normalization and store the data is right table. In this specific
assignment, the design of the database is based on the crowfoot notation and structured
dependencies of 3NF. 3NF is the last form is based on the first normalization form and second
normalization form. The report will cover the dependency diagram, crowfoot notation diagram,
and multivalued dependency diagram.
1. Dependency diagram:
A dependency diagram is used to define the main elements and the interdependencies of the
functional units and structure. This is helpful to display the workflow in a graphical manner.
This helps to specify the order or activities. in the dependency diagram, each node is called layer.
These layers represent projects, namespaces, and artifacts. The dependency diagram is helpful in
normalization process (“Dependency Diagrams: Guidelines - Visual Studio”,2018). The primary
key displays the value uniqueness in the tables.
Diagram
The diagram given above reflects the dependencies of the system activities and processes. The
dependency diagram represents the complete flow of work in the system. The attributes are
connected with other attributes in such a way that operation of the system is based on these
attributes. In the given diagram, 3 primary keys are there namely EMP_NAME, PROF_OFFICE,
and DEPT_CODE. These primary keys have their own set of attributes. These attributes display
the connection between those. This refers to the multi-valued or multi-formation of the diagram
of dependency.
2. Multivalued dependency
This refers to constraints that are helpful to display the relationship between 2 sets involving two
attributes. These need tuples for the relation representation between them. Attributes are
depended on each other. The third attribute is needed to present the occurrence of the attributes.
This occurs when 2 attributes of same table are not dependent on each other; instead of it these
attributes are dependent on third attribute (Chapple, M, 2019). Thus, it always needs at least
three attributes.
Diagram

The diagram given above represents the multivalued dependencies. In the diagram
PROF_OFFICE act like primary key and attributes are JOURNAL_CODE,
COMMITTEE_CODE, and ADVISEE. In this, third attribute is not needed as these attributes
are independent or self-dependent.
Single dependency
Diagram
3. 3NF structure dependencies
This is based on eth first normal form and second normal form. This refers that only columns of
foreign keys should be used for another table reference. Columns, other than parent table, should
not exist in reference table. This is helpful in the removal of data duplication. It also aids in the
maintenance of data integrity of the previous form of normalization and referral. There is
structure of a table that follows the dependencies of 3NF structure.
Diagram
The diagram given above displays the relation of the primary key and the attribute of it.
Employee table
Diagram
The diagram given above displays the employee table. This table displays the relation of primary
key and attribute of it. The primary key is EMP_NAME.
Professor information table
The diagram given above displays the professor information table. This table displays the
relation between the primary key and the attributes. The primary key is PROF_OFFICE
Department table
Diagram
The diagram given above displays the department table. This table displays the relation of
primary key and attributes of it. The primary key is DEPT_CODE.
4. Crow Foot notation diagram
Diagram

The diagram given above displays the crowfoot notation diagram of the whole system. This
diagram displays the relation between attributes and entities (Dybka, 2016). Crowfoot notation is
also known as ERD diagram. This is helpful to show the relationship between entities and
attributes.

Conclusion
To remove the flaws and issues from the database, the process of normalization is used. The
assignment covered the normalization structure of the database that is pre-defined according to
the brief. The report covered the whole scenario of the 3NF structure. Diagrams are used to
support the description. The report covered multivalued dependencies, crowfoot notation
diagram, and dependency diagram and 3NF diagram. The diagram of Crowfoot notation which
shows the relation between attributes and entities that is helpful in the unique identification.

References
Dependency Diagrams: Guidelines - Visual Studio. (2018). Retrieved 12 September 2019, from
https://docs.microsoft.com/en-us/visualstudio/modeling/layer-diagrams-guidelines?view=vs-
2019
Dybka, P. (2016). Crow’s Foot Notation. Retrieved 12 September 2019, from
https://www.vertabelo.com/blog/crow-s-foot-notation/
Chapple, M. (2019). Avoid Multivalued Dependencies by Breaking Data Into Multiple Tables.
Retrieved 12 September 2019, from https://www.lifewire.com/multivalued-dependency-1019755