如何格式化这个PostgreSQL查询以便能够与数据库一起运行:migrate

Question

我想要创建以下表格。我使用从ActiveRecord运行SQL

alter table items add column sumup numeric generated always as ( quantity * price + (quantity * price* fpa/100) ) stored;

这样做正确吗？

def change
create_table :items do |t|
t.string :itemName
t.string :prom
t.string :promCode
t.string :baseCode
t.string :desc
t.numeric :fpa
t.numeric :price
t.integer :quantity
t.string :monadaMe
t.string :familys
t.timestamps
end
ActiveRecord::Base.connection.execute(" alter table items add column sumup numeric generated always as ( quantity * price + (quantity * price* fpa/100) ) stored;")
end
end

Answer 1

只创建新列：

rails generate migration AddSumupToItems sumup:float

在您的model中，添加：

before_save :calculate_sumup
def calculate_sumup
sumup = ( quantity * price + (quantity * price* fpa/100) )
self.sumup = sumup
end