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

我想查询有些条件的交易：

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

如何在两个LIKE和Datamapper之间制作OR条件？

Answer 1

只需查询Transaction，但查询路径指向buyer.name和seller.name。

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

Answer 2

也许会这样：

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]

如何使LIKE与Datamapper之间的OR条件？

2 个答案: