Transactions

1What is a Transaction?✨

A transaction is a sequence of SQL operations that are treated as a single unit. If any part of the transaction fails, the entire transaction fails, ensuring data integrity.

2Why Use Transactions?🎯

• ✓ Maintain data accuracy and consistency
• ✓ Handle errors gracefully
• ✓ Ensure complete execution of operations
• ✓ Protect against data loss during failures

3Basic Transaction Commands💡

• In SQL, you can manage transactions using the following commands:
• BEGIN: Start a transaction
• COMMIT: Save the changes made during the transaction
• ROLLBACK: Revert changes if something goes wrong

4Example of a Transaction:🚀

To transfer money between accounts, you would use a transaction to ensure both the debit and credit operations succeed.

5BEGIN;🔍

UPDATE accounts SET balance = balance - 100 WHERE account_id = 1;

UPDATE accounts SET balance = balance + 100 WHERE account_id = 2;

6COMMIT;⭐

If any of these updates fail, you can use ROLLBACK to undo all changes.

7Transaction Properties🧩

• Transactions have four key properties known as ACID:
• Atomicity: All or nothing
• Consistency: Data must be valid before and after
• Isolation: Transactions do not interfere with each other
• Durability: Once committed, changes are permanent

8Using ROLLBACK for Error Handling🎈

If an error occurs during a transaction, it’s essential to revert the changes. Here's how you can use ROLLBACK:

9BEGIN;✨

UPDATE accounts SET balance = balance - 100 WHERE account_id = 1;

10-- Imagine this update fails🎯

ROLLBACK;

This ensures that no partial changes are saved, keeping the data consistent.

11What You'll Learn Next💡

• ✓ How to manage complex transactions
• ✓ Implementing error handling strategies
• ✓ Exploring transaction isolation levels
• ✓ Working with stored procedures for transactions