Module | Sequel::Plugins::DatasetAssociations::DatasetMethods
In: | lib/sequel/plugins/dataset_associations.rb

### Methods

associated

### Public Instance methods

associated(name)

For the association given by `name`, return a dataset of associated objects such that it would return the union of calling the association method on all objects returned by the current dataset.

This supports most options that are supported when eager loading. It doesn‘t support limits on the associations, or one_to_one associations that are really one_to_many and use an order to select the first matching object. In both of those cases, this will return an array of all matching objects.

[Source]

        # File lib/sequel/plugins/dataset_associations.rb, line 71
    71:         def associated(name)
    72:           raise Error, "unrecognized association name: #{name.inspect}" unless r = model.association_reflection(name)
    73:           ds = r.associated_class.dataset
    74:           sds = opts[:limit] ? self : unordered
    75:           ds = case r[:type]
    76:           when :many_to_one
    77:             ds.filter(r.qualified_primary_key=>sds.select(*Array(r[:qualified_key])))
    78:           when :one_to_one, :one_to_many
    79:             ds.filter(r.qualified_key=>sds.select(*Array(r.qualified_primary_key)))
    80:           when :many_to_many
    81:             ds.filter(r.qualified_right_primary_key=>sds.select(*Array(r.qualified_right_key)).
    82:               join(r[:join_table], r[:left_keys].zip(r[:left_primary_keys]), :implicit_qualifier=>model.table_name))
    83:           when :many_through_many
    84:             fre = r.reverse_edges.first
    85:             fe, *edges = r.edges
    86:             sds = sds.select(*Array(r.qualify(fre[:table], fre[:left]))).
    87:               join(fe[:table], Array(fe[:right]).zip(Array(fe[:left])), :implicit_qualifier=>model.table_name)
    88:             edges.each{|e| sds = sds.join(e[:table], Array(e[:right]).zip(Array(e[:left])))}
    89:             ds.filter(r.qualified_right_primary_key=>sds)
    90:           else
    91:             raise Error, "unrecognized association type for association #{name.inspect}: #{r[:type].inspect}"
    92:           end
    93:           ds = model.apply_association_dataset_opts(r, ds)
    94:           r[:extend].each{|m| ds.extend(m)}
    95:           ds
    96:         end

[Validate]