Erd Analysis

ERD Teaching Plan

What is a database? (what’s the difference between database and spreadsheet?)

* A database is an organized collection of data, ideal for storing and retrieving information.

* This means, it is a bunch of tables that hold all your information but they are linked, so you don’t get a lot of duplicated data.

* This makes it easier to find your information later, because you can do a search for the data you want, instead of seeing everything at once.

How to build a database?

* The most difficult part is figuring out where the data needs to go, but you can make this step easier by creating a diagram beforehand.

What kind of diagram?

* Entity Relationship Diagram (ERD)!

* It separates the information you need for each table and shows how the table links together.

* It is a great way to see the overall design of a database.

Where do we start?

What is an ERD?

* ERD is a graphical representation of a data requirement of a database. Meaning, it takes all of the parts of a databases and put it in box and line form.

Entity:

* ERD represents a person, place, or thing that you want to track in a database. In this case, STUDENT.

* This will become a table in the database.

* STUDENT is more of a container which will hold many students. Entity basically means all the things that are like students will be grouped together under STUDENT.

* Each occurrence of the entity is an “entity instance”. This will be each record or row in a table. In this case, each individual students (a single student is an instance of the entity STUDENT)

Attribute:

* An attribute describes various characteristics about an individual entity.

* These will become the columns in the table.

* It tells us more about the entity. In this case, each of those students now have a first name. FirstName is an attribute because it tells us more about each instance of STUDENT.

* It is important to know...