midMySQL
Implementing MySQL Triggers
Updated May 4, 2026
Short answer
Automated programs triggered by INSERT, UPDATE, or DELETE events.
Deep explanation
They run BEFORE or AFTER a change. Useful for auditing, enforcing rules, or syncing data across tables without application logic.
Real-world example
Automatically logging a history record when a user's role is changed.
Common mistakes
- Creating complex logic in triggers that is hard to debug and slow to execute.
Follow-up questions
- Can a trigger be recursive?