Query 1:
(CASE INV.PAYMENT_STATUS_FLAG WHEN 'N' THEN 'No' WHEN 'Y' THEN 'Yes' WHEN 'P' THEN 'Partial' ELSE INV.PAYMENT_STATUS_FLAG END )
Query 2:
NVL(IDSTR.BASE_AMOUNT, CASE INV.INVOICE_CURRENCY_CODE WHEN LDG.CURRENCY_CODE THEN NVL(IDSTR.AMOUNT,0) ELSE NULL END)