通过单向多对多，单向一对一，多向多对多或多向一对一从数据库取，赋值。如果考虑投入供热率高人通过键入两国(By one-way to multi - to - many, one-way one to one, multi - to - Multi - to - Multi - to - one - one - to - one from the database, assign values. If the high heating rate is taken into consideration, the people will enter the two countries)