postgresql 传递给#or 的关系必须在结构上兼容。不兼容的值：[:references]
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Relation passed to #or must be structurally compatible. Incompatible values: [:references]
提问by frostbite
I have two queries, I need an orbetween them, i.e. I want results that are returned by either the first or the second query.
我有两个查询，我需要or在它们之间进行查询，即我想要第一个或第二个查询返回的结果。
First query is a simple where()which gets all available items.
第一个查询是一个简单的查询where()，它获取所有可用的项目。
@items = @items.where(available: true)
Second includes a join()and gives the current user's items.
第二个包括一个join()并给出当前用户的项目。
@items =
@items
.joins(:orders)
.where(orders: { user_id: current_user.id})
I tried to combine these with Rails' or()method in various forms, including:
我尝试以or()各种形式将这些与 Rails 的方法结合起来，包括：
@items =
@items
.joins(:orders)
.where(orders: { user_id: current_user.id})
.or(
@items
.joins(:orders)
.where(available: true)
)
But I keep running into this error and I'm not sure how to fix it.
但是我一直遇到这个错误，我不知道如何解决它。
Relation passed to #or must be structurally compatible. Incompatible values: [:references]
采纳答案by Andrey Deineko
There is a known issue about it on Github.
According to this commentyou might want to override the structurally_incompatible_values_for_orto overcome the issue:
根据此评论，您可能想要覆盖structurally_incompatible_values_for_or以克服该问题：
def structurally_incompatible_values_for_or(other)
Relation::SINGLE_VALUE_METHODS.reject { |m| send("#{m}_value") == other.send("#{m}_value") } +
(Relation::MULTI_VALUE_METHODS - [:eager_load, :references, :extending]).reject { |m| send("#{m}_values") == other.send("#{m}_values") } +
(Relation::CLAUSE_METHODS - [:having, :where]).reject { |m| send("#{m}_clause") == other.send("#{m}_clause") }
end
Also there is always an option to use SQL:
此外，总有一个选项可以使用 SQL：
@items
.joins(:orders)
.where(
"orders.user_id = ? OR items.available = true",
current_user.id
)
回答by Rajdeep Singh
You can write the query in this good old way to avoid error
您可以用这种很好的旧方式编写查询以避免错误
@items = @items.joins(:orders).where("items.available = ? OR orders.user_id = ?", true, current_user.id)
Hope that helps!
希望有帮助！
