使用紅寶石計算每月總計算

Question

我有計算來列表自這個應用程序開始以來的總計。我只需要幫助計算當月的總計，我不知道該怎麼做。提前致謝。

item.rb的

class Item < ActiveRecord::Base 
    def profit_calc 
    sold_for - bought_for - fees - shipping rescue 0 
    end 

    def self.purchase_total 
    sum(:bought_for) 
    end 

    def self.fee_total 
    sum(:fees) 
    end 

    def self.shipping_total 
    sum(:shipping) 
    end 

    def self.sales_total 
    sum(:sold_for) 
    end 

    def self.profit_total 
    sold.sum(:sold_for) - sold.sum(:bought_for) - sold.sum(:fees) - sold.sum(:shipping) 
    end 

    def profit_margin_item 
    profit_calc/sold_for * 100 rescue 0 
    end 

    def self.profit_margin_total 
    profit_total/ sum(:sold_for) * 100 
    end 

    scope :visible, -> { where(sold: false) } 
    scope :sold, -> { where(sold: true) } 

    def self.search(search) 
    where("description LIKE ?", "%#{search}%") 
    end 
end 

statistics.html.erb

<h1 id="title">Statistics</h1> 
<br> 

<table align="center" style="width: 95%" class="table table-striped table-bordered"> 
    <thead> 
    <tr> 
     <th>Total Bought</th> 
     <th>Bought This Month</th> 
     <th>Total Sold</th> 
     <th>Sold This Month</th> 
    </tr> 
    </thead> 

    <tbody> 
    <tr> 
     <td><%= @items.count %></td> 
     <td><%= @items_month.count %></td> 
     <td><%= @items_sold.count %></td> 
     <td><%= @items_sold_month.count %></td> 
    </tr> 
    </tbody> 
</table> 

<table align="center" style="width: 95%" class="table table-striped table-bordered"> 
    <thead> 
    <tr> 
     <th>Total Purchases</th> 
     <th>Total Month Purchases</th> 
    </tr> 
    </thead> 

    <tbody> 
    <tr> 
     <td><%= number_to_currency(@items.purchase_total) %></td> 
     <td></td> 
    </tr> 
    </tbody> 
</table> 

<table align="center" style="width: 95%" class="table table-striped table-bordered"> 
    <thead> 
    <tr> 
     <th>Total Sales</th> 
     <th>Total Month Sales</th> 
    </tr> 
    </thead> 

    <tbody> 
    <tr> 
     <td><%= number_to_currency(@items.sales_total) %></td> 
     <td></td> 
    </tr> 
    </tbody> 
</table> 

<table align="center" style="width: 95%" class="table table-striped table-bordered"> 
    <thead> 
    <tr> 
     <th>Total Fees</th> 
     <th>Total Month Fees</th> 
    </tr> 
    </thead> 

    <tbody> 
    <tr> 
     <td><%= number_to_currency(@items.fee_total) %></td> 
     <td></td> 
    </tr> 
    </tbody> 
</table> 

<table align="center" style="width: 95%" class="table table-striped table-bordered"> 
    <thead> 
    <tr> 
     <th>Total Shipping</th> 
     <th>Total Month Shipping</th> 
    </tr> 
    </thead> 

    <tbody> 
    <tr> 
     <td><%= number_to_currency(@items.shipping_total) %></td> 
     <td></td> 
    </tr> 
    </tbody> 
</table> 

<table align="center" style="width: 95%" class="table table-striped table-bordered"> 
    <thead> 
    <tr> 
     <th>Total Profit</th> 
     <th>Total Month Profit</th> 
    </tr> 
    </thead> 

    <tbody> 
    <tr> 
     <td><%= number_to_currency(@items.profit_total) %></td> 
     <td></td> 
    </tr> 
    </tbody> 
</table> 

<table align="center" style="width: 95%" class="table table-striped table-bordered"> 
    <thead> 
    <tr> 
     <th>Total Margin</th> 
     <th>Total Month Margin</th> 
    </tr> 
    </thead> 

    <tbody> 
    <tr> 
     <td><%= number_to_percentage(@items.profit_margin_total, precision: 0) %></td> 
     <td></td> 
    </tr> 
    </tbody> 
</table> 

Answer 1

添加下列條件以獲取當月計算：

where(created_at: Time.zone.now.beginning_of_month..Time.zone.now.end_of_month) 

例如：

def self.purchase_total 
    where(created_at: Time.zone.now.beginning_of_month..Time.zone.now.end_of_month).sum(:bought_for) 
end 

如果你要廣泛地使用它，將其添加爲scope：

scope :current_month, -> { where(created_at: Time.zone.now.beginning_of_month..Time.zone.now.end_of_month) } 

現在：

def self.purchase_total 
    current_month.sum(:bought_for) 
end