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SQL for Beginners
The essential language for anyone working with data. Relational basics with PostgreSQL/MySQL: SELECT, filtering, CRUD, JOINs, aggregation, and simple schema design.
SQLLast updated 3 Feb 2026
Level 1: Thinking in Rows & Columns
Focus on understanding table structure and how to retrieve data.
Session 1: Database Basics & Tools
- What is an RDBMS? How a database differs from Excel.
- Set up PostgreSQL or MySQL (using Docker or tools like Laragon/XAMPP).
- Get familiar with a GUI (DBeaver or TablePlus) and the CLI.
Session 2: The SELECT Master
- Retrieving data with SELECT \* vs selecting specific columns.
- Giving columns an alias with AS.
- Limiting how many rows appear with LIMIT.
Session 3: Filtering (Finding Specific Data)
- Using WHERE to filter rows.
- Comparison operators:
=,<>,>, LIKE. - Combining conditions with AND, OR, and IN.
Level 2: Data Manipulation & Sorting
Learn how to shape the result set and change data.
Session 4: Sorting & Basic Math
- Ordering results with ORDER BY (ASC / DESC).
- Removing duplicate rows with DISTINCT.
- Simple calculations in a column (e.g.
price * quantity).
Session 5: Basic CRUD (Writing Data)
- INSERT: adding new rows to a table.
- UPDATE: changing existing rows (and why you must not forget WHERE!).
- DELETE: removing rows.
Level 3: Relationships & Aggregation (The Power of SQL)
Here you see why it’s called a relational database.
Session 6: Joining Tables (Connecting Data)
- Primary Key and Foreign Key.
- INNER JOIN: combining rows from two related tables (e.g. Orders + Users).
- A quick comparison with LEFT JOIN.
Session 7: Aggregation & Grouping
- Aggregate functions: COUNT, SUM, AVG, MIN, MAX.
- GROUP BY: grouping rows (e.g. total sales per product category).
- HAVING: filtering after grouping.
Level 4: Beginner Graduation (Structure & Safety)
Learn how to design and create your own tables safely.
Session 8: Schema Design (DDL)
- Creating tables with CREATE TABLE.
- Common SQL types: INT, VARCHAR, TEXT, TIMESTAMP.
- Adding constraints: NOT NULL, UNIQUE, and DEFAULT.
Session 9: Simple Normalization
- Why you shouldn’t put everything in one huge table.
- Splitting tables to avoid redundant (repeated) data.
Interested in this course? I offer mentoring and structured learning—get in touch to discuss your goals.