PostgreSQL & MySQL
The open-source relational databases behind most web applications, and SQL practice.
Beginner
Start here. No background needed beyond school maths.
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Beginner
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PostgreSQL Tutorial
Step-by-step lessons on SQL in ••••, from selecting and filtering to joins, window functions, indexes and stored procedures.
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Beginner
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SQL Tutorial (ThoughtSpot, formerly Mode)
A SQL course aimed at analysts, with a basic, intermediate and advanced track and real data to practise on.
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Beginner
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MySQL Tutorial
MySQL's own walkthrough: connect, create tables, load data and run the queries you will use every day.
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