Direkt zum Inhalt

Introduction to Relational Databases in SQL

Learn how to create one of the most efficient ways of storing data - relational databases!

Kurs Kostenlos Starten

4 Stunden13 Videos45 Übungen150.843 LernendeLeistungsnachweis

Kostenloses Konto erstellen

Google LinkedIn Facebook

oder

Durch Klick auf die Schaltfläche akzeptierst du unsere Nutzungsbedingungen, unsere Datenschutzrichtlinie und die Speicherung deiner Daten in den USA.

Trainierst du 2 oder mehr?

Versuchen DataCamp for Business

Beliebt bei Lernenden in Tausenden Unternehmen

Kursbeschreibung

Explore the Role of SQL in Relational Database Management

There are a lot of reasons why SQL is the go-to query language for relational database management. The main one is that SQL is a powerful language that can handle large amounts of data in complex ways and solve tricky analytical questions. In this course, you will gain an introduction to relational databases in SQL.

Learn how to create tables and specify their relationships, as well as how to enforce data integrity. Additionally, discover other unique features of database systems, such as constraints.

Create Your First Database

You begin the course by creating your first database with simple SQL commands. Next, you’ll learn how to update your database as the structure changes by migrating data and deleting tables.

In the final chapter, you will glue tables in foreign keys together and establish relationships that greatly benefit your data quality. Finally, you will run ad hoc analyses on your new database.

Understand the Basics of Relational Databases

By the end of the course, you will gain a basic yet essential understanding of SQL relational databases. They are widely used in various data science fields (from healthcare to finance) and have consequently become one of the crucial languages for data scientists. If you're interested in deepening your knowledge further, you may be interested in our SQL for Database Administrators, SQL Server Developer, and SQL Server for Database Administrators Tracks.

Für Unternehmen

Trainierst du 2 oder mehr?

Verschaffen Sie Ihrem Team Zugriff auf die vollständige DataCamp-Plattform, einschließlich aller Funktionen.

In den folgenden Tracks

Associate Data Engineer in SQL

SQL für Datenbankadministratoren

SQL Server-Entwickler

1
Your first database
Kostenlos
In this chapter, you'll create your very first database with a set of simple SQL commands. Next, you'll migrate data from existing flat tables into that database. You'll also learn how meta-information about a database can be queried.
Kapitel Jetzt Abspielen
Introduction to relational databases
50 xp
Attributes of relational databases
50 xp
Query information_schema with SELECT
100 xp
Tables: At the core of every database
50 xp
CREATE your first few TABLEs
100 xp
ADD a COLUMN with ALTER TABLE
100 xp
Update your database as the structure changes
50 xp
RENAME and DROP COLUMNs in affiliations
100 xp
Migrate data with INSERT INTO SELECT DISTINCT
100 xp
Delete tables with DROP TABLE
100 xp
2
Enforce data consistency with attribute constraints
After building a simple database, it's now time to make use of the features. You'll specify data types in columns, enforce column uniqueness, and disallow NULL values in this chapter.
Kapitel Jetzt Abspielen
Better data quality with constraints
50 xp
Types of database constraints
50 xp
Conforming with data types
100 xp
Type CASTs
100 xp
Working with data types
50 xp
Change types with ALTER COLUMN
100 xp
Convert types USING a function
100 xp
The not-null and unique constraints
50 xp
Disallow NULL values with SET NOT NULL
100 xp
What happens if you try to enter NULLs?
50 xp
Make your columns UNIQUE with ADD CONSTRAINT
100 xp
3
Uniquely identify records with key constraints
Now let’s get into the best practices of database engineering. It's time to add primary and foreign keys to the tables. These are two of the most important concepts in databases, and are the building blocks you’ll use to establish relationships between tables.
Kapitel Jetzt Abspielen
Keys and superkeys
50 xp
Get to know SELECT COUNT DISTINCT
100 xp
Identify keys with SELECT COUNT DISTINCT
100 xp
Primary keys
50 xp
Identify the primary key
50 xp
ADD key CONSTRAINTs to the tables
100 xp
Surrogate keys
50 xp
Add a SERIAL surrogate key
100 xp
CONCATenate columns to a surrogate key
100 xp
Test your knowledge before advancing
100 xp
4
Glue together tables with foreign keys
In the final chapter, you'll leverage foreign keys to connect tables and establish relationships that will greatly benefit your data quality. And you'll run ad hoc analyses on your new database.
Kapitel Jetzt Abspielen
Model 1:N relationships with foreign keys
50 xp
REFERENCE a table with a FOREIGN KEY
100 xp
Explore foreign key constraints
100 xp
JOIN tables linked by a foreign key
100 xp
Model more complex relationships
50 xp
Add foreign keys to the "affiliations" table
100 xp
Populate the "professor_id" column
100 xp
Drop "firstname" and "lastname"
100 xp
Referential integrity
50 xp
Referential integrity violations
50 xp
Change the referential integrity behavior of a key
100 xp
Roundup
50 xp
Count affiliations per university
100 xp
Join all the tables together
100 xp

Für Unternehmen

Trainierst du 2 oder mehr?

Verschaffen Sie Ihrem Team Zugriff auf die vollständige DataCamp-Plattform, einschließlich aller Funktionen.

In den folgenden Tracks

Associate Data Engineer in SQL

SQL für Datenbankadministratoren

SQL Server-Entwickler

In anderen Tracks

SQL Server für Datenbankadministratoren

Mitwirkende

Sumedh Panchadhar

Chester Ismay

Mona Khalil

Voraussetzungen

Intermediate SQL

Timo Grossenbacher

Head of Newsroom Automation at Tamedia

Was sagen andere Lernende?

Melden Sie sich an 15 Millionen Lernende und starten Sie Introduction to Relational Databases in SQL Heute!

Kostenloses Konto erstellen

Google LinkedIn Facebook

oder

Durch Klick auf die Schaltfläche akzeptierst du unsere Nutzungsbedingungen, unsere Datenschutzrichtlinie und die Speicherung deiner Daten in den USA.