工作人员只能有一辆车,车辆一次只能属于一名工人。 有3层可能的实现我知道:
1.1对1关系
Vehicle(Id, Number)
Worker(Id, Name, VehicleId)
--> This allows two workers have the same vehicle.
2.
Worker(Id, Name)
Vehicle(Id, Number, WorkerId)
--> This allows worker to have two vehicles.
3.
Worker(Id, Name)
Vehicle(Id, Number)
WorkersVehicles(Id, VehicleId, WorkerId)
--> This allows each worker to have many vehicles and each vehicle to belong to many workers.
以上都不可以描述所期望的1:1的关系。
如何在数据库和实体框架中描述这种1:1关系?
难道工人必须有车? – awright18