我试图从现有的表列中计算值,并在外部变量上使用它。让我的表列为:["id","unit_price","quantity","extras_1","extras_2"],我使用sql命令作为引用,在rails中展示了我想要做的事情。排序,我无法通过查询看到派生属性值。quantity-unit_price*quantity*discount AS price_after_
Create or replace Trigger in_vehiclefor each rowIF(:new.PURCHASE_DATE < '12/31/2016')raise_application_error(20001, 'the Hire date must be between 2017 and 2020');if(:new.PURCHASE_DATE > '12/31/2016') and