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SQL Mastery
Introduction
Setup
SELECT, WHERE, Aggregations
Grouping, Ordering, More Aggregations
Functions & Dates
JOINs
Math & String Functions
Subqueries
Window Functions
Data Definition Language (DDL)
Views & Temporary Tables
Lessons ☰
JOINs
How JOINs actually work, when to use each type, and how to combine tables without breaking your results. Clear examples with common pitfalls to avoid.