Class 3

This is based on the 8/5/19 Dat602 Class.

Relational model is the most common model around the world. Around 95% of models are of this type, recently some other types of model have come about, these have problem which is why they haven’t over taken Relational Models. Breaking down this information allows us to better understand why we use relationship models.

For our project we will use story board almost as a stand in for Conceptual Model.

Aggregate Model and Network model are No-SQL model and require a relational model to work.

Normally a set is not ordered, but aggregate models have information dumped into the system and join it together, it’s a way of access data and run it, which is why they use this, not good for places where there will be a lot of changes to the date.

Network model takes relationships to the extreme because everything has a possible like to another piece of data.

This information is important to understanding how exactly how relationship model work which is the model we will use.

In a relation ship model if you create references to other element like with a network model each element gain a reference to the other. This is what foreign keys are.

Relational model have sets of data which are all logically related and putting into a ‘table’.

We are creating a simple program which access a data base constantly we will go with relational models as that is the industry standard.

We may use any logical math with in SQL which will be helpful as there are many basic mathematical function which we might need with in our project such as order a high score chart.

Cod is the creator of the relational model.

After the creation of relational model IBM was the first company to adopted the model.

Chris Date worked out how to normalize the database model and allowing them to be fix if they are broken. He also worked for IBM and worked with Cod on the Relationship model.

The point is that each data value only has to be stored once allowing us to avoid update error where only one has to be updated.

Data independence, this is the concept that we can create a database which is independent from the program that we are creating so we can re-use it with another program.

SQL is a very user friendly language which allow the use to select and edit specific part of a database if the column in the database is specified then they don’t have to be ordered otherwise they will be place in the order they are entered.

Some functions of SQL are aggravating columns together this is useful for things such as making composite key or to joining names together for user names.