Free course

SQL Course

Learn relational database fundamentals, create and change tables, write useful queries, connect related data, and use SQL safely in applications.

5 modules · 40 lessons · No signup

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What you'll learn

Design a small relational database and write safe SQL queries that create, read, update, and connect its data.

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Course contents

  1. Database fundamentals

    Databases, DBMSs, relational structure, schemas, and SQL.

    1. What is a Database? And a DBMS?
    2. Relational Databases
    3. The Relational Model
    4. Introduction to SQL
    5. Tables, rows, and columns
    6. When you need a database
    7. Check your understanding: database fundamentals
  2. Tables and data

    Types, constraints, and the commands that change stored data.

    1. SQL, creating a table
    2. Choose column data types
    3. SQL, adding data to a table
    4. SQL, how to update data
    5. SQL, how to delete data and tables
    6. SQL, Handling empty cells
    7. SQL, how to update a table structure
    8. Use constraints to protect data
    9. Check your understanding: tables and data
  3. Query data

    Select, filter, sort, group, aggregate, and limit results.

    1. SQL, how to use SELECT
    2. Filter rows with WHERE
    3. Sort and limit results
    4. Summarize with aggregate functions
    5. Group and filter summaries
    6. Return distinct values
    7. Check your understanding: SQL queries
  4. Relationships and joins

    Keys, one-to-many and many-to-many relations, joins, and views.

    1. SQL, Unique and Primary keys
    2. Connect rows with foreign keys
    3. Model one-to-many relationships
    4. Model many-to-many relationships
    5. SQL Joins
    6. INNER JOIN and LEFT JOIN
    7. SQL Views
    8. Check your understanding: joins and relationships
  5. Databases in practice

    Choose a database, protect queries, and keep changes reliable.

    1. How to install SQLite on macOS
    2. Choose SQLite, PostgreSQL, or MySQL
    3. Use indexes deliberately
    4. Keep related changes together with transactions
    5. SQL injection
    6. Use parameterized queries
    7. Store password hashes, not passwords
    8. Plan backups and schema migrations
    9. Check your understanding: databases in practice