Rollback a Failed Transfer

Easysql

Write a transaction that attempts to transfer 300 from account id 1 to account id 2, but then rolls it back instead of committing. Debit account 1 by 300, credit account 2 by 300, then ROLLBACK.

sql
CREATE TABLE accounts (
  id INTEGER PRIMARY KEY,
  balance INTEGER NOT NULL
) ENGINE=InnoDB;

Sample data:

sql
INSERT INTO accounts (id, balance) VALUES (1, 1000), (2, 500);

Example 1

Input

(none)

Output

id	balance
1	1000
2	500

Reference: START TRANSACTION; UPDATE accounts SET balance = balance - 300 WHERE id = 1; UPDATE accounts SET balance = balance + 300 WHERE id = 2; ROLLBACK; — the balances must equal the original seed values exactly, proving the transaction left no trace.

Rollback a Failed Transfer

Related Problems

Input (stdin)

Output