ruby on rails - How can i get the value of primary_value in activerecord has_many definition? -

# == schema information # # table name: books # id           :integer  # owner_id     :integer  # table name: users # id           :integer # name         :string  # table name: shared_books_records # user_id      :integer # book_id      :integer  books id: 1, owner_id: 1 # jack id: 2, owner_id: 2 # tom id: 3, owner_id: 1 # jack  users id: 1, name: "jack" id: 2, name: "tom" 

jack has 2 books , tom has 1 book.

shared_books_records user_id: 1, book_id: 2 

so jack borrowed tom's book. jack should have 3 books.

class user   def all_books     join_sql = <<-sql.squish!       left outer join shared_books_records         on shared_books_records.user_id = books.assignee_id     sql     condition = <<-sql.squish!        books.owner_id = :user_id or         shared_books_records.user_id = user_id     sql      book.joins(join_sql).where(condition, user_id: id)   end end 

i think it's not good, activerecord association better. want redefine it.

has_many :all_books,           -> {             primary_key_value = xxxx    # want value             join_sql = <<-sql.squish!              left outer join shared_books_records                on shared_books_records.user_id = books.assignee_id            sql             condition = <<-sql.squish!              books.owner_id = :user_id or               shared_books_records.user_id = user_id            sql             joins(join_sql).unscope(:where).where(condition, user_id: primary_key_value)          },           class_name: book, foreign_key: :owner_id 

but don't know how value of primary_key in scope.

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my solution

has_many :all_books,       -> (user) {         primary_key_value = user.id    # want value         join_sql = <<-sql.squish!          left outer join shared_books_records            on shared_books_records.user_id = books.assignee_id        sql         condition = <<-sql.squish!          books.owner_id = :user_id or           shared_books_records.user_id = :user_id        sql         joins(join_sql).unscope(:where).where(condition, user_id: primary_key_value)      },       class_name: book, foreign_key: :owner_id 

to books can this

class user   has_many :user_books   has_many :books, through: :user_books end  class userbook   belongs_to :books   belongs_to :users end  class book   has_many :user_books   has_many :users, through: :user_books end  # table name: books # id           :integer  # owner_id     :integer  # table name: users # id           :integer  # table name: user_books (previously shared_books_record) # user_id      :integer # book_id      :integer   def all_ books   #lets id has value user_id   user = user.find(id)   all_books = user.books #this should return array of books belongs current user end