求助一列为某值时候，另一列显示为空，怎么写SQL
当currency列为RMB时，其他两列显示为空值。
[解决办法]
SELECT
DebitAmount = (CASE CurrencyCode WHEN 'RMB' THEN NULL ELSE CreditAmount END),
CreditAmount = (CASE CurrencyCode WHEN 'RMB' THEN NULL ELSE DebitAmount END),
CurrencyCode
FROM tb
SELECT
CreditAmount = (CASE CurrencyCode WHEN 'RMB' THEN NULL ELSE CreditAmount END),
DebitAmount = (CASE CurrencyCode WHEN 'RMB' THEN NULL ELSE DebitAmount END),
CurrencyCode
FROM tb
