Module: Sequel::Plugins::ManyThroughMany::ClassMethods

Defined in:
lib/sequel/plugins/many_through_many.rb

Instance Method Summary collapse

Instance Method Details

#many_through_many(name, through, opts = {}, &block) ⇒ Object

Create a many_through_many association. Arguments:

  • name - Same as associate, the name of the association.

  • through - The tables and keys to join between the current table and the associated table. Must be an array, with elements that are either 3 element arrays, or hashes with keys :table, :left, and :right. The required entries in the array/hash are:

    • :table (first array element) - The name of the table to join.

    • :left (middle array element) - The key joining the table to the previous table. Can use an array of symbols for a composite key association.

    • :right (last array element) - The key joining the table to the next table. Can use an array of symbols for a composite key association.

    If a hash is provided, the following keys are respected when using eager_graph:

    • :block - A proc to use as the block argument to join.

    • :conditions - Extra conditions to add to the JOIN ON clause. Must be a hash or array of two pairs.

    • :join_type - The join type to use for the join, defaults to :left_outer.

    • :only_conditions - Conditions to use for the join instead of the ones specified by the keys.

  • opts - The options for the associaion. Takes the same options as associate, and supports these additional options:

    • :left_primary_key - column in current table that the first :left option in through points to, as a symbol. Defaults to primary key of current table. Can use an array of symbols for a composite key association.

    • :right_primary_key - column in associated table that the final :right option in through points to, as a symbol. Defaults to primary key of the associated table. Can use an array of symbols for a composite key association.

    • :uniq - Adds a after_load callback that makes the array of objects unique.



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# File 'lib/sequel/plugins/many_through_many.rb', line 144

def many_through_many(name, through, opts={}, &block)
  associate(:many_through_many, name, opts.merge(through.is_a?(Hash) ? through : {:through=>through}), &block)
end