Entities

If you didn’t understand anything this week, you might learn something here. {6}

by Asim K
Ladies, gentlemen, and classmates: I’ve got the perfect solution for you in the case that you’ve been staring at the whiteboard for the past week and all you can make out is pretty boxes in blue expo marker. I ran across an intuitive article written by Hui-Lien Tung and Hsiang-Jui King titled “A Web-Based Tool for Teaching Data Modeling” in our own ACM Digital Library. read more...

Choosing the right tools for a database {1}

by Edwin T
The article i read goes over the basics of a database and what people need to know when considering implementing a database for their business.  The author talks about database design and management and also recommends software to make the process easier.  Under the “Databases Defined” section of the article, the author goes over the entities and attributes and how relationships can be established between entities in order to share data.  The products that the author recommends are FileMaker Pro 11.  With this anybody can create a database or ad-hoc report.  If the user is a bit more familiar with databases then the author discusses Microsoft Access 2010 and Alpha Five v10 Developer to create highly customized solutions using the databases as back-ends. read more...

Conceptually understanding data models {2}

by Jasmine C
In summary, the article I read reiterates the importance of having a well designed data model.  Without a good data model, then the information in the database based on that model is not going to correspond.  The data model is going to contain the information about the “entities , their associations and attributes within the intended business” (Huang).  As we all know, if the data model is messed-up, the the database that it is based off is not going to have a correct representation of reality.  Something that many people need to understand is that conceptually, data modeling is very easy to mess up.  This is true especially for student database designers.  Cognitively speaking, student designers do not yet contain the ability to effectively understand the reasoning behind data modeling techniques.  Domain knowledge and cognitive fit are two variables that student designers need to understand in order for them to progress to expert designers.  These two variables are essential for conceptual data modeling. read more...

Breaking Down Relational Databases {1}

by Evin C
The article I have chosen is a peer reviewed article from Kansas State University about how students conceptualize entity relationships. This article explains in depth how entity relationship design can vary from student to student and not one individual way is correct. It goes on to explain and give examples of how the way we perceive these relationships can ultimately affect our work beyond college. Depending on how specific we are with these relational entities or how general we are can show if we will miss important concepts within a business that will affect efficiency. Examples are given from using associative entities in a business to applying an ERD to relational model. Michael Chilton uses this article to explain how us as students need to be aware of the environment we are working in as well as the situation at hand because there is no one way to create an entity relationship. As a student we have to thrive to understand the basic concepts and use them to our advantage in the real world. read more...

Something About Supertype Entity {Comments Off on Something About Supertype Entity}

by Peter C
Summary:

According to the article, Supertype entities are similar but different from Subtype entities. Supertype and subtype entities have a relationship such as parent to children. They both share some common attribute within themselves. For a subtype entity, it has some unique attributes that are different from the other subgroups entities. Some of the attributes are also different from the supertype entity.  For example, People can be your super entity and for your subtype, it can be vendors, employees, and customers. These primary key must be the same as the supertype entity. As for the subtype entities, it can contain some attribute that are not the same as each other. read more...