Rails 3;在where子句中添加'和'

Question

我有以下查询返回方向为nil的所有注册...

@registrations = Registration.includes(:orientation).
                  where(orientations: {:class_date => nil})

我需要添加第二个过滤器，所以我只是一个特定的姓氏，所以像......

@registrations = Registration.includes(:orientation).
                  where(orientations: {:class_date => nil AND :last_name => "smith"})

但是，此语法不正确。如何添加'AND'或＆amp;＆amp;声明到这个where子句的结尾？

Answer 1

所有键/值对都加入where() AND：

Registration.includes(:orientation).
  where(orientations: {:class_date => nil}, :last_name => "smith")