Entity class as a property of another entity class

If an entity class is a property of another entity class, it is OK to assign an object to the property if it is assigned a value, and if more than one object is assigned to that property, it can be received with the list collection, just like the text message in the development

, if you reply to multiple text messages, use the list collection to install t them.

I was told by the technical director this morning that he wrote a lot of kinds in a file, and I usually write the class in a separate file, which I'm very curious about. In the QQ group and people discussed a bit, feel that the class should be a separate file to write, so whether it is later maintenance, or review changes, will be very convenient. There is also an all entity class plus partial. You need to manually change the entity class, write a file yourself, and if it is an entity class as a property of another entity class, if the entity class as a property has no effect at the back, it can be written in a file.

Entity class as a property of another entity class