LEFT JOIN vs RIGHT JOIN in MySQL Explained

LEFT and RIGHT JOIN are mirror images of each other: both keep all rows from one side of the join. In practice, almost everyone standardises on LEFT JOIN — here's why, and how the two relate.

Key Points

• LEFT JOIN keeps every row of the first (left) table
• RIGHT JOIN keeps every row of the second (right) table
• Any RIGHT JOIN can be rewritten as a LEFT JOIN by swapping table order
• Teams prefer LEFT JOIN for readability — the 'main' table comes first
• Unmatched side shows NULLs in both cases
• Chaining multiple RIGHT JOINs gets confusing fast; avoid it