Bank vs Ledger Mismatches

Compare the ledger with the bank statement by txn_id. Return txn_id, ledger_amount, bank_amount and issue ('amount mismatch', 'missing in bank' or 'missing in ledger'), ordered by txn_id.

Table schema

Ledger(txn_id INT PRIMARY KEY, amount INT)
Bank(txn_id INT PRIMARY KEY, amount INT)

Sample data

Ledger
txn_id | amount
1 | 100
2 | 250
3 | 75

Bank
txn_id | amount
1 | 100
2 | 200
4 | 50