Hibernate basic ing

1. The object class corresponds to the table; the common attribute in the object class corresponds to the table field.

2. Design Principles of entity classes:

2.1 implement a default (No parameter) constructor (required ).

2.2 an identifier property is provided (optional ).

2.3 use a non-final class (Optional). If you use a final class that does not implement any interfaces, you cannot use delayed loading.

2.4 is the persistent field life accessor and variable flag (optional ).

3. Primary Key Generation Policy

UUID, native, assigned, increment (not applicable to cluster environments), identity, and sequence.