Rails活动记录包括条件

Question

I have this use case.

Project:
  has_many :assignments

Assignment:
  has_many :assignments_users, class_name: "AssignmentsUsers"
  has_many :assignees, through: :assignments_users, source: :user

assignments_users: is simply user_id and assignment_id.

I'd like to be able to do something like this.

projects = Project.includes(:assignments, {assignments: :assginments_users}).where("assignments.assignments_users.user_id = 6")

Where if I was to access assignments from a given project in the list, I would only see assignments where one of the users assigned is a user with id 6.

is this even do able?

I was thinking maybe I make an extra has_many my_assignments, (user_id) -> { where(match_something_to_my_user_id) }

is that even possible?

Answer 1

Your example is pretty close to something that should work:

projects = Project.
  includes(assignments: :assignments_users).
  where(assignments_users: { user_id: 6 })

Alternatively, it might be neater to approach from the other side:

Assignment:
  belongs_to :project

User:
  has_many :assignments_users, class_name: "AssignmentsUsers"
  has_many :assignments, through: :assignments_users
  has_many :active_projects, through: :assignments, source: :project

my_user.active_projects