midT-SQL
Difference between INNER and LEFT JOIN
Updated May 17, 2026
Short answer
INNER returns matches, LEFT returns all left rows.
Deep explanation
LEFT JOIN includes unmatched rows with NULLs.
Real-world example
Listing all employees even without orders.
Common mistakes
- Confusing output row counts.
Follow-up questions
- When to use LEFT JOIN?
- Performance difference?