Querying data with SQL
Ask a database real questions and get answers you can defend. You write every query yourself against sample datasets and check the result in the sandbox.
- hours
- 24
- units
- 4
- lessons
- 24
- Certificate level
- 3
About this course
Ask a database real questions and get answers you can defend. You write every query yourself against sample datasets and check the result in the sandbox.
Who it is for
Analysts, marketers, product people and anyone who works with spreadsheets and wants to go further.
Paces
Standard · Flexible
What you will be able to do
- Select, filter and sort rows from a table
- Join tables and aggregate with GROUP BY
- Write subqueries and use common table expressions
- Explain a query result and its limits
Curriculum
4 units · 24 topics · 24 hours
01Reading one table6 lessons · 6 hours
Outcome: Select, filter and sort rows from a table
- L01Tables, rows and columns60 min
- L02SELECT and choosing columns60 min
- L03Filtering with WHERE60 min
- L04AND, OR, IN and BETWEEN60 min
- L05Sorting and limiting results60 min
- L06NULL and missing values60 min
- ✓Unit check: show this outcome with evidence
02Joins and aggregation6 lessons · 6 hours
Outcome: Join tables and aggregate with GROUP BY
- L07Keys and relationships60 min
- L08INNER JOIN60 min
- L09LEFT JOIN and unmatched rows60 min
- L10COUNT, SUM and AVG60 min
- L11GROUP BY60 min
- L12Filtering groups with HAVING60 min
- ✓Unit check: show this outcome with evidence
03Subqueries and CTEs6 lessons · 6 hours
Outcome: Write subqueries and use common table expressions
- L13Subqueries in WHERE60 min
- L14Subqueries in FROM60 min
- L15Common table expressions60 min
- L16CASE expressions60 min
- L17Date and text functions60 min
- L18Window functions, a first look60 min
- ✓Unit check: show this outcome with evidence
04Explaining results6 lessons · 6 hours
Outcome: Explain a query result and its limits
- L19Checking a result for mistakes60 min
- L20Duplicates and double counting60 min
- L21Reading a query plan, simply60 min
- L22Writing readable SQL60 min
- L23Stating what a result does not show60 min
- L24Capstone: ten queries on a dataset60 min
- ✓Unit check: show this outcome with evidence
How each live lesson runs
Every topic is one live lesson of an hour. Your instructor and mentor are AI, and they say so.
Whiteboard · Idea
Tables, rows and columns
- Marek Quint explains one idea at a time on the whiteboard, in plain words.
How you are assessed
What you hand in
Ten queries on a sample dataset, checked in the sandbox
Final check
Ten-query sandbox check on an unseen dataset
Certificate level 3
You showed the skill
Your evidence was assessed against the course's standard, and a person signs this certificate.
Who teaches
Every lesson has a named AI teacher and a mentor who keeps you on track. Both are AI, and every screen says so.
- AI instructorMarek Quint
Programming, SQL, web and IT support: everything is tried in the sandbox, and tests decide what works.
- AI mentorBastian Kwan
Keeps every learner on track across courses: pacing, reminders, what to do next, when to ask for help. Never gives answers to the check.
First class · try it now
Sit the first class before you decide
Seven steps, about ten minutes, no account: learn, check, produce, get assessed, defend it in a short viva and leave with a proof card.
More in this category
Digital, AI & Software
Introduction to programming with Python
Write real Python from the first hour. You run every line in the sandbox, read the errors, fix them and build up to a small program that passes automated tests.
Digital, AI & Software
Your first website with HTML and CSS
Build a real one-page website from an empty file: clean HTML, modern CSS layout, a page that works on a phone and passes basic accessibility checks.
Digital, AI & Software
IT support fundamentals
Learn how computers and networks fit together, then work simulated support tickets the way a help desk does: triage, diagnose, fix and record.
