Database Modeling Experience Online Tutoring
Experiences through Database Modeling
Learning through database modeling and designing is supposed to enhance the business knowledge of the graduates, their skills and future employment prospects. I believe that peer assessments and self-reflection can help the learners in reflecting on their role within the group and their individual contributions towards the project (Rienties, 2014). I also believe that peer-assessments can lead to satisfaction amongst students while reducing stress. As I was progressing in this project, I learnt a lot about how data can be managed and how databases can be created within a given business context.
[hbupro_banner id=”6299″]This instructional case about database development for Torrens University Australia (TUA) helped me in understanding the system designing process in real. It helped me in designing an actual system for the university students where the data of students could be recorded. The developed databases are aimed at helping and facilitating the university staff in managing data of students enrolled, courses that students enrolled in and the staff allocated to the courses. In doing so, four different versions of database were constructed named as
Data modeling has also been used for designing the database at the conceptual, physical and logical levels. It is a technique that I used in documenting the software system using the diagrams and symbols. The highest level of abstraction for data modeling is known as Entity Relationship Diagram (ERD) (Al-Masree, 2015). ERD acted as a blueprint of the existing database that allowed the designer for creating an accurate design as per the given case scenario and requirements of the company. Through ERD, I was allowed to focus on the data flows and understood the flow of relationships between the entities to be chosen. In short, ERD allowed me to make a better visual representation under the given scenario.
First, I used the ERD before constructing the database in the tabular form. By making ERD first, I was able to create perfect relationships of entities with each other. ERD helped me in describing the interrelated things of interest in one domain of knowledge. It actually gave me the snapshot of data structures. After ERD, I carried on with database normalization that is a process of creating the table design by assigning specific entities and attributes of the entities to each table in the database. After defining the entities, their attributes and showing their relationships with each other, I was able to sketch out the logical structure of the intended database. The reason to carry on with data normalization was to eliminate the redundancy in the data while ensuring that the data dependencies make sense. Through data normalization, I ensured that the data is logically stored and amount of space utilized is reduced (Mitrovic, 2003).
During the project, I had to create 30 rows of data by choosing specific database objects and their attributes and show it in version 1. By updating the V1.0 and adding records, attributes and rows of data, three more versions were successfully created in Excel. I used three major entities in this database as main objects i.e. Teachers, Students and Courses. These entities had unique attributes too that worked as distinguishing characteristic of the entity. For entity of Teacher, I used ID, First Name, Last Name, Gender, Email, Phone and Age as attributes while for “Student”, I used one extra attribute of Class Semester. For “Course”, I used the attributes of ID, Name, Credit Hours and Course Code. All the objects were distinguished from each other based on the following attributes that I constructed in ERD (see appendix below for ERD). During data normalization process, specific tabulation identified the primary keys in a particular table. I specifically used the primary keys and foreign keys in each project tables. The primary keys will enable the users in identifying the record in the table e.g. every student will have a unique primary key based on either roll number or registration code. The foreign keys were sourced in from primary keys to be used in another table.
[hbupro_banner id=”6296″]I also constructed One-to-One, One-to-many and many-to-many relation for clearing the cardinality of the objects and their respective attributes (Rowen, 2001). In one-to-many relationships, the local table was formed having one row that was associated with many rows in another table while on one-to-one, only one row was associated with the other row. In many-to-many relationships, the relationships between two lists of entities in many rows are linked together. In the given case, the example of one-to-one relationship would be that when one student takes admission in the TUA. For one-to-many, the example would be when one teacher has to teach 50 students in one class. For many-to-many the example would be when 50 different students will be taught 10 different courses.
Throughout the project, I faced several challenges associated with searching on the main entities of the database. After deciding on the relevant database entities, I carefully chose the attributes that was a little bit complex. Several attributes could be used related to academic database modeling, so the most specific ones were used while keeping the given case in mind. Another challenge was to create the relations of entities with each other like one-to-one, one-to-many and many-to-many. While creating database, specifically I faced the difficulty in forming many-to-many relationships as in Excel it was not possible. In order to create the many-to-many relationship between entities, I had to use VLOOPUP function for presenting the data.
By carrying this project, I was able to understand the concept of data modeling and in real understand how the databases can be created using relationships. I understood that without creation of relationships, the whole database does not work. Without creation of one-to-one and one-to-many relationships, the data cannot stay accurate and might become redundant. The importance of creating relationships was so important in this project. I also believe that by using ERD model, my overall data flow became more efficient.
REFERENCES
Al-Masree, H. K. (2015). Extracting Entity Relationship Diagram (ERD) from relational database schema. International Journal of Database Theory and Application, 8(3), 15-26.
Mitrovic, A. (2003). Supporting self-explanation in a data normalization tutor. Supplementary proceedings, AIED.
Rienties, B. (2014). Student Experiences of Self-Reflection and Peer Assessment in Providing Authentic Project-Based Learning to Large Class Sizes. Facilitating learning in the 21st century: leading through technology, diversity and authenticity, 117-136.
Rowen, W. (2001). An analysis of many-to-many relationships between fact and dimension tables in dimensional modeling. International Workshop on Design and Management of Data Warehouses (DMDW 2001), Interlaken Switzerland.
