-- Add foreign currency amount support to balance letter tables
ALTER TABLE `balance_letter_data`
  ADD COLUMN `foreign_currency` varchar(10)   DEFAULT NULL AFTER `balance_amount`,
  ADD COLUMN `foreign_amount`   decimal(15,2) DEFAULT NULL AFTER `foreign_currency`;

ALTER TABLE `balance_confirmation_detail`
  ADD COLUMN `foreign_currency` varchar(10)   DEFAULT NULL AFTER `balance_amount`,
  ADD COLUMN `foreign_amount`   decimal(15,2) DEFAULT NULL AFTER `foreign_currency`;

-- Example: customer with USD foreign balance
-- UPDATE balance_letter_data SET foreign_currency='USD', foreign_amount=1500.00 WHERE code='CUST001';
