- relations = Relation.find_by_sql("select e.* from current_relations e,current_relation_members em where " +
- "e.visible=1 and " +
- "em.id = e.id and em.member_type='node' and em.member_id in (#{visible_nodes.keys.join(',')})")
- relations += Relation.find_by_sql("select e.* from current_relations e,current_relation_members em where " +
- "e.visible=1 and " +
- "em.id = e.id and em.member_type='way' and em.member_id in (#{way_ids.join(',')})")
+ relations = Array.new
+ if visible_nodes.length > 0
+ relations += Relation.find_by_sql("select e.* from current_relations e,current_relation_members em where " +
+ "e.visible=1 and " +
+ "em.id = e.id and em.member_type='node' and em.member_id in (#{visible_nodes.keys.join(',')})")
+ end
+ if way_ids.length > 0
+ relations += Relation.find_by_sql("select e.* from current_relations e,current_relation_members em where " +
+ "e.visible=1 and " +
+ "em.id = e.id and em.member_type='way' and em.member_id in (#{way_ids.join(',')})")
+ end