AvailableFree
Why does SQL exist?
Understand why companies use databases, then write your first query to solve a real problem.
- Level
- Complete beginner
- Duration
- 35 to 45 min
- Syllabus
- 5 micro-lessons · 5 activities
- Account required
- No, to start
One skill · One concrete result
Progress in SQL, one skill at a time.
Choose a focused goal, follow the sequence and practise in the browser. Beta access is free for 30 days with no card required.
Available programmes
Twelve skills ready to practise.
Each micro-course brings together only the lessons and exercises needed for its goal without duplicating your progress.
AvailableIncluded in beta access
SQL, PostgreSQL, MySQL and SQL Server: what is the difference?
Understand the language, systems and dialects so you can choose the right documentation and write portable SQL with judgement.
- Level
- Beginner
- Duration
- 45 to 60 min
- Syllabus
- 5 micro-lessons · 6 activities
- Account required
- Beta account — free access for 30 days, no payment card
AvailableIncluded in beta access
Keep data reliable with constraints
Stop invalid data in the right place with types, keys and constraints.
- Level
- Beginner / intermediate
- Duration
- 60 min
- Syllabus
- 6 micro-lessons · 8 activities
- Account required
- Beta account — free access for 30 days, no payment card
AvailableIncluded in beta access
Secure an operation with transactions
Make several related changes succeed or fail together.
- Level
- Intermediate
- Duration
- 60 to 75 min
- Syllabus
- 6 micro-lessons · 8 activities
- Account required
- Beta account — free access for 30 days, no payment card
AvailableIncluded in beta access
Automate PostgreSQL with triggers
React to a data event without hiding business logic unnecessarily.
- Level
- Intermediate
- Duration
- 75 to 90 min
- Syllabus
- 6 micro-lessons · 10 activities
- Account required
- Beta account — free access for 30 days, no payment card
AvailableIncluded in beta access
Create views and materialized views
Reuse query logic and decide when its result should be materialized.
- Level
- Intermediate
- Duration
- 60 to 75 min
- Syllabus
- 5 micro-lessons · 7 activities
- Account required
- Beta account — free access for 30 days, no payment card
AvailableIncluded in beta access
Speed up a query with indexes and EXPLAIN
Read a simple plan and add an index only when it solves a measured problem.
- Level
- Intermediate
- Duration
- 75 to 90 min
- Syllabus
- 6 micro-lessons · 9 activities
- Account required
- Beta account — free access for 30 days, no payment card
AvailableIncluded in beta access
PostgreSQL functions and procedures
Encapsulate database-side logic while understanding its cost and alternatives.
- Level
- Intermediate / advanced
- Duration
- 90 min
- Syllabus
- 6 micro-lessons · 9 activities
- Account required
- Beta account — free access for 30 days, no payment card
AvailableIncluded in beta access
Roles, permissions and data security
Grant only the access required and understand row-level security.
- Level
- Intermediate
- Duration
- 60 to 75 min
- Syllabus
- 5 micro-lessons · 7 activities
- Account required
- Beta account — free access for 30 days, no payment card
AvailableIncluded in beta access
SQL for Power BI: theoretical foundations
Understand how to prepare clean data at the right grain before working in Power BI.
- Level
- Intermediate
- Duration
- 75 to 90 min
- Syllabus
- 6 micro-lessons · 8 activities
- Account required
- Beta account — free access for 30 days, no payment card
AvailableIncluded in beta access
Window functions for business analysis
Compare, rank and calculate changes without losing row-level detail.
- Level
- Intermediate
- Duration
- 90 min
- Syllabus
- 6 micro-lessons · 10 activities
- Account required
- Beta account — free access for 30 days, no payment card
AvailableIncluded in beta access
Control data quality with SQL
Turn data-quality suspicions into repeatable, prioritised checks.
- Level
- Intermediate
- Duration
- 60 to 90 min
- Syllabus
- 6 micro-lessons · 9 activities
- Account required
- Beta account — free access for 30 days, no payment card