Object-link structure mode (Chapter 1)
1. Identity Field)
Definition: a database ID domain stored in the object to maintain the identity between the memory object and the database row.
Key Selection: Unique, constant, can quickly perform equal operations, quickly obtain the type of the next key (can be a single or combination, but pay attention to the date and time type; can be a table unique key, it can also be the unique key of the database, but be alert when there is table inheritance)
In-Object Representation: You can simply use the integer key to create a key class for the combination (generic class or each object can correspond to a class independently)
Obtain the new key value: automatically generate the domain, database counter, guid, and key table (table name + next valid value)
Time to use: domain model and data entry
2. Foreign key ing
Definition: foreign key ing maps object references to foreign keys in the database
Time to use: applicable to all associations except many-to-many associations
3. Associate table ing
4. Dependency ing
5. Embedded value
6. serialize lob
7. Single Table inheritance
8. Class table inheritance
9. Specific table inheritance
10. inherit the er