优雅地对AWS Athena中的多个列求和，但不包括空值

问题描述

我必须通过在AWS Athena中添加其他几列来创建total_costs，total_proceeds和total_net_loss列。我还必须将nulls替换为zeros，否则结果将为null。我尝试使用sum()函数，但仅在单列上起作用。以下查询完成了我想做的事情，但是看起来很不优雅。还有其他更优雅的方法来汇总Athena中的列吗？

SELECT loan_identifier,monthly_reporting_period,current_actual_upb,current_loan_delinquency_status,(COALESCE(foreclosure_costs,0) + COALESCE(property_preservation_and_repair_costs,0) + COALESCE(asset_recovery_costs,0) + COALESCE(miscellaneous_holding_expenses_and_credits,0) + COALESCE(associated_taxes_for_holding_property,0)) AS total_costs,(COALESCE(net_sale_proceeds,0) + COALESCE(credit_enhancement_proceeds,0) + COALESCE(repurchase_make_whole_proceeds,0) + COALESCE(other_foreclosure_proceeds,0)) AS total_proceeds,current_actual_upb + (current_actual_upb * ((current_interest_rate/100 - 0.0035)/12)*DATE_DIFF('day',last_paid_installement_date,disposition_date)/30) + (COALESCE(foreclosure_costs,0)) - (COALESCE(net_sale_proceeds,0)) AS total_net_loss
FROM performance_data;

解决方法

结合使用SUM和COALESCE，如下所示：

SELECT SUM(COALESCE(y,0) + COALESCE(z,0)) AS aggregate_sum_of_y_and_z
FROM (
  VALUES (1,2),(NULL,3),(2,1)) AS x (y,z)