Relational Databases

Over the next couple of pages, we'll briefly go over some of the fundamental concepts concerning relational databases . In general, we're assuming that you've had some experience with relational databases, and that these ideas are not entirely new to you.

If this is new to you, or if you feel shaky on this topic, don't worry—we'll provide some additional resources that you can use to learn (or review) the basics that you'll need for this course.

Resources

If you'd like to spend some time going over the basic concepts of relational databases, you can check out Udacity's free course Intro to Relational Databases .

I also recommend this video, An Introduction to Relational Databases , which introduces the thinking behind relational databases, how they resolve issues of inconsistent data entry, and how they allow different pieces of data to relate to one another using primary keys (we'll talk more about primary keys in a moment).

QUIZ QUESTION: :

We just talked about several key characteristics that databases have. Can you match each characteristic with the correct description?

ANSWER CHOICES:

Efficient storage of strings, numbers, booleans, etc.

Multiple users of a web application can write and read data at the same time, while the data is kept in a consistent and accurate state.

You can access data later, after it was created.

All the users of a web application can access the same data source

Description	Database Characteristic
Ability to efficiently store many types of data
Concurrency control
Shared source of truth
Persistence

SOLUTION:

Description	Database Characteristic
Ability to efficiently store many types of data	Efficient storage of strings, numbers, booleans, etc.
Concurrency control	Multiple users of a web application can write and read data at the same time, while the data is kept in a consistent and accurate state.
Shared source of truth	All the users of a web application can access the same data source
Persistence	You can access data later, after it was created.

Check off all the qualities of a relational database management system

All data is stored in tables

All data is stored in nodes and edges

Every column has a data type

Every row has a data type

It provides constraints and triggers to enforce data integrity

SOLUTION:

• All data is stored in tables
• Every column has a data type
• It provides constraints and triggers to enforce data integrity