rails3上的ruby-在rails3中使用IN运算符查找位置

Question

我正在尝试运行下面这样的sql

select name from appointments where location_id in (2,3,4)

以下内容不起作用。我正在使用PostgreSQL

a = [2,3,4]
Appointment.select(:name).where("location_id IN ?", a)
ActiveRecord::StatementInvalid: PGError: ERROR:  syntax error at or near "2"
LINE 1: ... FROM       "appointments"  WHERE     (location_id IN 2,3,4)
                                                                 ^
: SELECT     name FROM       "appointments"  WHERE     (location_id IN 2,3,4)

Answer 1

您可以使用这个：

Appointment.select(:name).where(:location_id => [2,3,4])

希望这能帮助

Answer 2

我不知道rails，但在我看来，你需要这样做：

Appointment.select(:name).where("location_id IN (?)", a)

即在CCD_ 2周围放置括号。