hibernate详解（Hibernate详解）.docVIP

hibernate详解（Hibernate详解） 1.Hibernate retrieval method Answer: the navigation object graph retrieval in OID 3 HQL 4 QBC retrieval retrieval retrieval and retrieval of local SQL 1. navigation object graph retrieval method. (according to the loaded object, navigate to other objects.) 2.OID search. (according to the OID object to retrieve the object.) 3.HQL search. (object oriented query language for HQL.) 4.QBC search. (using the QBC (Qurey By Criteria) API to retrieve the object.) 5. local search methods SQL. (using a local database SQL query.) The difference between 2.Forward and Global-Forward Answer: Forward Action is based on the value of return to find the corresponding JSP. When a Action return with a value, this can be written in the Global-Forward Forward element. The three state 3. persistent object, representing the meaning of. Answer: a temporary state - just use the new statement to create, not be persistent, not in the session cache. Persistent state -- has been persistent in the session cache. Free - has been persistent, but not in the session cache. What is the 4, three kinds of search strategies, which are suitable for what kind of situation? Answer: immediate retrieval: Advantages: completely transparent to the application, disadvantages: select statement number. Application: the class level. Delayed retrieval: Advantages: loading which objects are determined by the application, can avoid redundant and execute select statements to avoid loading does not need to access the object, save the memory space and improve the efficiency of retrieval. Disadvantages: proxy class instances of the application to access the free state, must ensure that it has been initialized in the persistence time. Application: one to many or many to many relationship. The application does not require immediate access or no access to objects. Urgent left outer join search: Advantages: completely transparent to the application, regardless of whether the object is in a persistent s