Question

根据我的应用，我需要根据一系列条件获取用户。

@usersSet1 = XXX based on a bunch of conditions

@usersSet2 = XXX based on a bunch of different conditions

@usersSet3 = XXX based on a bunch of even more different conditions

然后我想结合3，并取得前100名记录。有关使用Rails完成此操作的任何想法？感谢

Answer 1

您应该在模型中定义范围：

# model
scope :set1, where(some_conditions), ...
scope :set2, where(some_conditions), ...
scope :set3, where(some_conditions), ...
scope :top_100, limit(100)

为这些范围指定适当的名称。当然，你需要通过某种东西来order。然后你可以打电话：

@usersSet1 = User.set1
@usersSet2 = User.set2
@usersSet3 = User.set3

@usersset123 = User.set1.set2.set3.top_100

它将AND set1，set2和set3中的所有条件。

Answer 2

最好的方法是执行一次SQL查询，撤回具有这些条件的字段。例如：

@users = User.all(select => "city,state,last_name,first_name,…", :limit => 100)

现在你拥有了所有的专栏。所以你继续：

@usersSet1 = @users.select{|a| a.state == 'Charlotte' && a.state == 'NC') #pulls back users in Charlotte
@usersSet2 = @users.select{|b| b.last_name == 'Smith' } #pulls back users that have the last name of Smith.
@usersSet3 = @users.select{|b| b.first_name == ('John' || 'Joe') } #pulls back users that have the first name of John or Joe.

依此类推......在我看来，这更具可扩展性。

rails - 构建查询，将它们组合起来？

2 个答案: