Database Design Tools That Will Help You Learn SQL Faster

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From the course by Duke University

Managing Big Data with MySQL

1958 ratings

Duke University

Managing Big Data with MySQL

1958 ratings

Course 4 of 5 in the Specialization Excel to MySQL: Analytic Techniques for Business

This course is an introduction to how to use relational databases in business analysis. You will learn how relational databases work, and how to use entity-relationship diagrams to display the structure of the data held within them. This knowledge will help you understand how data needs to be collected in business contexts, and help you identify features you want to consider if you are involved in implementing new data collection efforts. You will also learn how to execute the most useful query and table aggregation statements for business analysts, and practice using them with real databases. No more waiting 48 hours for someone else in the company to provide data to you – you will be able to get the data by yourself! By the end of this course, you will have a clear understanding of how relational databases work, and have a portfolio of queries you can show potential employers. Businesses are collecting increasing amounts of information with the hope that data will yield novel insights into how to improve businesses. Analysts that understand how to access this data – this means you! – will have a strong competitive advantage in this data-smitten business world.

From the lesson

Understanding Relational Databases

Welcome to week 1! This week you will learn how relational databases are organized, and practice making and interpreting Entity Relationship (ER) diagrams and relational schemas that describe the structure of data stored in a database. <p>By the end of the week, you will be able to:<ul><li>Describe the fundamental principles of relational database design <li>Interpret Entity Relationship (ER) diagrams and Entity Relationship (ER) schemas, and</li><li>Create your own ER diagrams and relational schemas using a software tool called ERDPlus that you will use to aid your query-writing later in the course.</li></ul><p>This week’s exercises are donated from a well-known Database Systems textbook, and will help you deepen and strengthen your understanding of how relational databases are organized. This deeper understanding will help you navigate complicated business databases, and allow you to write more efficient queries. At the conclusion of the week, you will test your understanding of database design principles by completing the Week 1 graded quiz.</p> <p>To get started, please begin with the video “Problems with Having a Lot of Data Used by a Lot of People.” <p>As always, if you have any questions, post them to the Discussions. <p>I hope you enjoy this week's materials!

Database Design Tools That Will Help You Learn SQL Faster4:12

How Entity-Relationship Diagrams Work8:53

Database Structures Illustrated by Entity-Relationship Diagrams6:22

Relational Schemas9:57

Meet the Instructors

Daniel Egger
Executive in Residence and Director, Center for Quantitative Modeling
Pratt School of Engineering, Duke University
Jana Schaich Borg
Assistant Research Professor
Social Science Research Institute

Last video we heard about how relational databases use set theory and

relational algebra to allow us to pull pretty much whatever data we want out of

a relational database.

In this video, we are going to talk about how you learn to tell a database what you

want out of it.

The way you ask a database to give you data is to write and

execute what is called a query.

The language or

code you use to write the queries is SQL or structured query language.

SQL is used by every relational database management system, abbreviated DBMS,

even if there are some slight nuanced differences across platforms.

As a data analyst, you are almost guaranteed to interact with the relational

database at some point in your career, if not everyday.

But even if you are interacting with databases that do not use traditional

relational structures, most database management systems try really

hard to create query languages that look as similar as possible to SQL.

Because SQL is so intuitive and so ubiquitous in the database world.

Therefore, no matter what database platform you end up working with,

it will advance your career if you learn SQL.

And the more you understand about SQL truly works,

the greater edge you will have in the marketplace.

I have a slightly different view of learning SQL than you will find in many of

the courses out there.

As a data analyst, you will be making lots of queries, but you will not be setting up

or maintaining databases unless you are working in an early stage startup.

Nonetheless, my experience has taught me that you will learn queries

much faster and your queries will be much more efficient

if you know some of the basic tools that are used to set up databases.

In addition, if you know how to read the documents database engineers and

managers create, your life will be much easier when you start writing queries and

you'll be less likely to make certain kinds of mistakes that lead you to

misinterpret your data.

So I really wanted to find ways to give students in this course exposure to

the tools that are used to design a database.

Fortunately, the person who wrote my favorite tools was very generously willing

to share his resources with us.

Perhaps not surprisingly, he also shares my view about learning SQL.

Here he is.

>> Hello, my name is Nenad Jukic, and I'm a Professor of Information Systems at

Quinlan School of Business at Loyola University Chicago.

It is difficult to learn SQL as a pure beginner if

one doesn't know some basic things about relational database model itself.

The main concept in relational database model

that connects tables of a concept of a foreign key.

And if a person doesn't really understand why is it there,

how it works, it makes learning SQL very unnatural.

So the best way to learn SQL in my opinion is to first learn

few basic things about database design and modeling before we start learning SQL.

>> Entity-Relationship diagrams or ER diagrams

are one of the database design tools that will be useful for you to understand.

ER diagrams are pictures that represent how

the data in a database are supposed to be connected or related to one another.

Relational schemas are another database tool you will benefit from learning how to

read and understand.

Relational schemas are basically maps of the database.

Sometimes relational schemas are missing important information, that is contained

in an ER diagram, so it is useful to practice and understand both tools.

Nenad has made a very well design online program that

will allow us to practice making both ER diagrams and relational schemas.

So here's what we're going to do for the rest of this week.

In the next few videos, we are going to go over some practical concepts of

how relational databases are organized, and go over how to make ER diagrams and

relational schemas.

Then Nenad will show you himself how to use the great online tool he created.

After practicing with a couple assignments,

you will answer some questions about the relational schema of a real

life department store data set we will be using in the later weeks of the course.

And you will make your own ER diagram and relational schema for

the real life startup data set we will be using.

This will prepare you how to start learning how to answer business questions

about those data sets next week when we start writing SQL queries.

Are you excited?

I hope so.

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