为什么代码库中没有模型定义而是数据库中的表？

I have been trying to figure out why I cannot find a model in my code even though the table is in the database. The table is a cross reference table from a many to many relationship. Does active record handle this specially? The table only contains two foreign keys and audit fields. The reason I am getting even more confused is because we have other cross reference tables that I can see the model for.I have been trying to figure out why I cannot f