Transactions in MySQL

What is a Transaction?

Bank Transfer Example

START TRANSACTION;
UPDATE accounts SET balance = balance - 500 WHERE id = 1;
UPDATE accounts SET balance = balance + 500 WHERE id = 2;
COMMIT;   -- both updates saved together

Key Commands

• START TRANSACTION — begin.
• COMMIT — save all changes.
• ROLLBACK — undo all changes.

Summary

• A transaction groups statements into one all-or-nothing unit.
• COMMIT saves; ROLLBACK undoes. Essential for money/critical updates.

Transaction क्या है?

Bank Transfer Example

START TRANSACTION;
UPDATE accounts SET balance = balance - 500 WHERE id = 1;
UPDATE accounts SET balance = balance + 500 WHERE id = 2;
COMMIT;   -- दोनों updates साथ save

मुख्य Commands

• START TRANSACTION — शुरू।
• COMMIT — सारे changes save।
• ROLLBACK — सारे changes undo।

सारांश

• Transaction statements को एक all-or-nothing unit में बाँधता है।
• COMMIT save करता है; ROLLBACK undo। Money/critical updates के लिए ज़रूरी।