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.
[show source]
# File lib/sequel/plugins/dataset_associations.rb, line 73 def associated(name) raise Error, "unrecognized association name: #{name.inspect}" unless r = model.association_reflection(name) ds = r.associated_class.dataset sds = opts[:limit] ? self : unordered ds = case r[:type] when :many_to_one ds.filter(r.qualified_primary_key=>sds.select(*Array(r[:qualified_key]))) when :one_to_one, :one_to_many ds.filter(r.qualified_key=>sds.select(*Array(r.qualified_primary_key))) when :many_to_many ds.filter(r.qualified_right_primary_key=>sds.select(*Array(r.qualified_right_key)). join(r[:join_table], r[:left_keys].zip(r[:left_primary_keys]), :implicit_qualifier=>model.table_name)) when :many_through_many fre = r.reverse_edges.first fe, *edges = r.edges sds = sds.select(*Array(r.qualify(fre[:table], fre[:left]))). join(fe[:table], Array(fe[:right]).zip(Array(fe[:left])), :implicit_qualifier=>model.table_name) edges.each{|e| sds = sds.join(e[:table], Array(e[:right]).zip(Array(e[:left])))} ds.filter(r.qualified_right_primary_key=>sds) when :pg_array_to_many ds.filter(Sequel.expr(r.primary_key=>sds.select{Sequel.pg_array_op(r.qualify(r[:model].table_name, r[:key])).unnest})) when :many_to_pg_array ds.filter(Sequel.function(:coalesce, Sequel.pg_array_op(r[:key]).overlaps(sds.select{array_agg(r.qualify(r[:model].table_name, r.primary_key))}), false)) else raise Error, "unrecognized association type for association #{name.inspect}: #{r[:type].inspect}" end ds = model.apply_association_dataset_opts(r, ds) r[:extend].each{|m| ds.extend(m)} ds end