How to make your framework pseudo-ORM

How can we make our framework pseudo-Orm? I thought for a moment in the morning and suddenly came to the inspiration.
1. Get a complete entity
We usually obtain a primary object. We hope to obtain the set of other entities contained by the object by the way. For example, orderentity wants to access the orderitementity set by the way. Since datatable can only obtain its own, it is necessary to obtain the complete object set at the entire dataset level.
First, filldatasetbyid must be used to obtain all the data of the order corresponding to orderid.
Secondly, use the getentity of the returned orderdataset to get orderentity "entity of the master table". orderentity has an array of orderitementity.
In this way, you can access the orderitementity array of orderentity to obtain orderitementity.
2. Set a complete entity
This is relatively simple. It must be the entity of the Set primary table.
If it is added, you only need to use orderdataset. createentity () as orderentity to obtain
If it is modified or deleted, it must be the orderset. getentity () as orderentity after filldatasetbyid to modify and delete it, and then set back
3. Entity should allow the delete function
Entity can be marked as deleted. It must be obtained by getentity after filldatasetbyid. The free entity is not supported.