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采用:include & :conditions in a cary on railkous request?
原标题:using :include && :conditions in a ruby on rails SQL request?

我不想说什么。

我愿获得所有<<>Carts, 其中有cart_stage.stage/strong>,等于35(这是一个单独的表格,一个汽车有多个阶段)。

弹片舱是像

id ----- cart_id ----- stage
1 ------- 123 ---------- 20
2 ------- 123 ---------- 35
3 ------- 102 ---------- 35

我现在试图这样做:

# Cart model
  has_one :top_stage, :foreign_key =>  cart_id , :class_name => "CartStage", :order =>  stage 

# Cart controller
  @carts = Cart.find :all, :order =>  created_at DESC , :include => :top_stage, :conditions => ["top_stage.stage = ?", 35]  

这使我:

SQLite3::SQLException: no such column: top_stage.stage: SELECT DISTINCT "carts".id FROM "carts" WHERE (top_stage.stage = 35)  ORDER BY created_at DESC LIMIT 40 OFFSET 0

希望一切都有意义,任何帮助都将受到高度赞赏。

* A/63/150。

最佳回答

我实际上设法这样做。 我想要的是:

@carts = Cart.find :all, :order =>  created_at DESC , :joins => :top_stage, :conditions => { :cart_stages => { :stage => 35 } }

感谢一切帮助!

问题回答

这可能是:

@carts = Cart.find(:all, :order =>  carts.created_at DESC , :include => :top_stage, :conditions => { "cart_stages.stage" => 35 })

请注意,你在条件上而不是在协会名称中使用表格的名称,但你确实在include选项中使用协会的名称。

在可能的情况下,你或许应当利用散射方法表达条件,使你的声明简单明了。 当你需要复杂的<代码>OR或>>类型逻辑,即阵列式证明是必要的。

铁路3的表述方式较好:

@carts = Cart.order( carts.created_at DESC ).include(:top_stage).where( top_stages.stage  => 35)

不清楚您的<代码>cart_stages为何 页: 1

在你包括字面卡的地方,你需要使用真实表格和栏目名称,not铁路协会名称。 因此,你需要:<代码>:conditions => [“cart_stage.stage = ?”, 35],而不是top_stage





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