1

我会很简短，直截了当。我正在尝试将三个表连接在一起，以获得所有未归档客户的总开票时间乘以开票费率。这是我目前在我的控制器中拥有的：

@total_due = Client.find(:all, :joins => [:invoices, :invoice_line_items], :select => "SUM(invoice_line_items.hours * invoice_line_items.rate) as total", :group => "clients.archive, invoices.paid_status HAVING clients.archive = false AND invoices.paid_status = false")

我的模型如下所示：

# /models/clients.rb
class Client < ActiveRecord::Base
    has_many :invoices
    has_many :invoice_line_items, :through => :invoices
end

# /models/invoices.rb
class Client < ActiveRecord::Base
    belongs_to :client
    has_many   :invoice_line_items
end

# /models/invoice_line_items.rb
class Client < ActiveRecord::Base
    belongs_to :invoice
end

因此，正如您从我的控制器中的代码中看到的那样，我正在尝试获取与未归档客户相关的所有发票的总工时费率，但他们尚未付款。我的控制器中的上述代码在某处复制数据，因为我的数字比它应该的高很多。

我正在尝试构建的查询是这样的：

SELECT SUM(invoice_line_items.hours * invoice_line_items.rate) AS total FROM clients INNER JOIN invoices ON clients.id = invoices.client_id INNER JOIN invoice_line_items ON invoices.id = invoice_line_items.invoice_id GROUP BY clients.archive, invoices.paid_status HAVING clients.archive = false AND invoices.paid_status = false

有人可以解释或弄清楚为什么我在我的 rails 查询中得到重复的数据吗？我有一种感觉，它只是加入表格的方式与我预期的不同。我对 Rails 也还是很陌生。谢谢！

更新：这是 rails 正在生成的查询：

select sum(invoice_line_items.hours * invoice_line_items.rate) as total
from clients
inner join invoices on invoices.client_id = clients.id
inner join invoices invoices_clients_join on invoices_clients_join.client_id = clients.id 
inner join invoice_line_items on invoice_line_items.invoice_id = invoices_clients_join.id 
group by clients.archive, invoices.paid_status
having clients.archive = false and invoices.paid_status = false
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1 回答 1

0

invoices好的，我只需删除控制器中的连接，就可以让 rails 生成我需要的查询。我想结合invoice_line_items加入和:through关系正在创建许多加入。

我的控制器现在看起来像这样：

@total_due = Client.find(:all, :joins => :invoice_line_items, :select => "SUM(invoice_line_items.hours * invoice_line_items.rate) as total", :group => "clients.archive, invoices.paid_status HAVING clients.archive = false AND invoices.paid_status = false")
于 2012-11-14T21:02:38.993 回答