Beginner LevelSQL & MySQL
What are the ACID properties of relational database transactions?
❓ Interview Prompt: Explain ACID transaction guarantees: Atomicity, Consistency, Isolation, and Durability, and transaction management (`START TRANSACTION`, `COMMIT`, `ROLLBACK`).
ACID represents the 4 core guarantees of database transactions:
1
Atomicity: "All or Nothing". Every statement in a transaction succeeds, or the entire transaction is rolled back.
2
Consistency: Transactions transition the database from one valid state to another, preserving all constraints.
3
Isolation: Concurrent transactions execute without interfering with one another.
4
Durability: Once a transaction commits, its changes persist permanently, even through power outages.
Code Implementation Example
sql
START TRANSACTION;
-- Deduct from sender account
UPDATE accounts SET balance = balance - 100.00 WHERE id = 1;
-- Credit to receiver account
UPDATE accounts SET balance = balance + 100.00 WHERE id = 2;
-- Commit transaction if both updates succeed!
COMMIT;💡Executing a multi-statement ACID transaction with COMMIT.
🎯 Interview Key Takeaway
ACID guarantees that relational database transactions process reliably without partial state corruption.
#SQL#ACID#Transactions#Commit#Beginner
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