Before writing any SQL queries, it’s important to understand the underlying data. In this chapter, we’ll discover the role of SQL in creating and querying relational databases. Using a database for a local library, we will explore database and table organization, data types and storage, and best practices for database construction. 

Databases

What are the advantages of databases?

Data organization

Tables

Picking a unique ID

Setting the table in style

Our very own table

Data

At your service

Finding data types

Options

VARCHAR

NUMERIC

Choice of type

Relational Databases

Learn your first SQL keywords for selecting relevant data from database tables! After practicing querying skills in a database of books, you’ll customize query results using aliasing and save them as views so they can be shared. Finally, you’ll explore the differences between SQL flavors and databases such as PostgreSQL and SQL Server.

Introducing queries

SQL strengths

Developing SQL style

Querying the books table

Writing queries

Making queries DISTINCT

Aliasing

VIEWing your query

SQL flavors

Comparing flavors

Limiting results

Translating between flavors

Congratulations!

Querying

Much of the world's raw data—from electronic medical records to customer transactions—is stored in relational databases, and the ability to manipulate and retrieve this data is an increasingly sought-after skill.

In this two-hour introduction to SQL, you'll learn the theory and practice of extracting and organizing data. You'll cover database best practices, SQL queries, and popular SQL variants like PostgreSQL and SQL Server. By the end of the course, you’ll have hands-on experience in SQL and the grounding to start applying it to your projects.


<h2>Get an Introduction to SQL in Two Hours</h2> 
Much of the world's raw data—from electronic medical records to customer transaction histories—lives in organized collections of tables called relational databases. Being able to wrangle and extract data from these databases using SQL is an essential skill within the data industry and in increasing demand.
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In just two hours, you'll get to know the theory and the practice through bite-sized videos and interactive exercises where you can put your new-found skills to the test.
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<h2>Learn how Relational Databases are Organized</h2> 
SQL is an essential language for building and maintaining relational databases, which opens the door to a range of careers in the data industry and beyond. You’ll start this course by covering data organization, tables, and best practices for database construction.
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<h2>Write Your First SQL Queries</h2> 
The second half of this course looks at creating SQL queries for selecting data that you need from your database. You’ll have the chance to practice your querying skills before moving on to customizing and saving your results.
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<h2>Understand the Difference Between PostgreSQL and SQL Server</h2> 
PostgreSQL and SQL Server are two of the most popular SQL flavors. You’ll finish off this course by looking at the differences, benefits, and applications of each. By the end of the course, you’ll have some hands-on experience in learning SQL and the grounding to start applying it to projects or continue your learning in a more specialized direction.

Get started in SQL in just two hours - find out how relational databases are structured, query them, and learn the differences between different SQL types. 

Our very own table

“Introduction to SQL”

Exercise instructions

Hands-on interactive exercise

Introduction to SQL

Chapter 1: Relational Databases

Chapter 2: Querying

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