Rails 4 内部连接在同一张表上

Question

在 Rails 4 应用程序中，我有以下关联：

User has_many :bookings
Booking belongs_to :client, class_name: "User"

我正在尝试通过表格进行 JOIN 以获取 Booking 和 CLIENT：

User.joins("INNER JOIN bookings on users.id = bookings.user_id").joins("INNER JOIN users on bookings.client_id = users.id") 

返回：

PG::DuplicateAlias: ERROR:  table name "users" specified more than once

有没有办法获取这 2 个关联？

Answer 1

试试

User.joins("INNER JOIN bookings on users.id = bookings.user_id").joins("INNER JOIN users AS bookings_user on bookings.client_id = bookings_user.id")

注意users AS bookings_user