ruby - 如何在 LIKE 和 Datamapper 之间建立 OR 条件？

Question

我有3个相关模型：

class Transaction
  include DataMapper::Resource    
  property :id, Serial     
  property :volume, Float
  property :deal_date, Date  
  belongs_to :buyer
  belongs_to :seller
end

class Seller
  include DataMapper::Resource    
  property :id,         Serial
  property :name,   String      
  has n, :transactions
end

class Buyer
  include DataMapper::Resource    
  property :id, Serial
  property :name,   String, :length => 255, :index => true, :unique => true
  has n, :transactions
end

我想对具有某些条件的交易进行查询：

x < volume < y
and
a < deal_date < b
and
( buyer.name like key_word OR seller.name like key_word )

如何使用 Datamapper 在两个 LIKE 之间创建 OR 条件？

Answer 1

简单地查询Transaction，但查询路径到buyer.name和seller.name。

Transaction.all('buyer.name.like' => 关键字) | Transaction.all('seller.name.like' => 关键字)

Answer 2

也许这会做：

key_word = '%blabla%'
trs = Transaction.all condition: [
        '   buyer_id IN (SELECT id FROM buyer WHERE name LIKE ?) 
         OR seller_id IN (SELECT id FROM seller WHERE name LIKE ?)', 
      key_word, key_word]