SQL Join types overview and tutorial

SQL Joins - The Ultimate Guide - Essential SQL

SQL JOIN Types Explained: Types, Uses, and Tips to Know

SQL GROUP BY Guide - Essential SQL

Group By in SQL Server with CUBE, ROLLUP and GROUPING SETS Examples

Use SQL Group By in Excel VBA – Skills and Automation

A step-by-step walkthrough of SQL Inner Join

Inner Join vs Outer Join

SQL multiple joins for beginners with examples