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MySQL Transactions

A Transaction in MySQL is a set of SQL statements that are executed as a single unit. Transactions are used to ensure the ACID properties: Atomicity, Consistency, Isolation, and Durability. They are useful for operations that require multiple steps to succeed or fail together.

Key Concepts

  • START TRANSACTION: Begins a transaction.
  • COMMIT: Saves the changes made in the transaction.
  • ROLLBACK: Reverts the changes made in the transaction.

Example: Using Transactions

START TRANSACTION;
UPDATE accounts SET balance = balance - 100 WHERE account_id = 1;
UPDATE accounts SET balance = balance + 100 WHERE account_id = 2;
COMMIT;

Code Explanation: This transaction transfers 100 units from account 1 to account 2. If any step fails, you can use ROLLBACK to undo the changes.

Best Practices

  • Always use transactions for operations that involve multiple updates to ensure data consistency.
  • Use ROLLBACK to handle errors and maintain data integrity.

Key Takeaways

  • Transactions ensure that a series of operations are completed successfully or not at all.
  • They help maintain data consistency and integrity in the database.
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