Touch 'n Go — Wallet Topup Reconciliation

Finance flagged a wallet reconciliation gap: the payment gateway's topup log and the wallet's own ledger don't always agree. You have two tables — confirmed topups and the wallet ledger (which mixes credits AND debits in one table) — and no pre-built reconciliation view. Four sequential steps: total each side, join them into a discrepancy, then name the single account with the largest gap.

Schema

▸tng_topups

topup_id	SERIAL
user_id	INT
amount	INT
topped_up_at	TIMESTAMP

▸tng_ledger

ledger_id	SERIAL
user_id	INT
entry_type	TEXT
amount	INT
posted_at	TIMESTAMP

4 steps

1Total topped-up amount per account
2Total credited amount per account
3Compute each account's topup-vs-ledger discrepancy
4Name the account finance should open a ticket on

Basic

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