005 --- preliminary query interface

Query session. createquery (string hql)Method;

* The session. createquery () method of hibernate uses the hql (Hibernate query statement) statement to query objects.

* Hql: it is the query object, for example, "from user", where from is not case sensitive, while user is case sensitive because it is an object. Yesuser class

* Returns the query object.

* After this statement is executed, Hibernate automatically generates the SQL statement of the corresponding database based on the database adapter configured in the configuration file. For example:

 

Hibernate: Select user0 _. ID as id0 _, user0 _. name as name0 _, user0 _. password as password0 _, user0 _. createtime as createtime0 _, user0 _. expiretime as expiretime0 _ from user user0 _

 

QueryPaging query:

 

The complete code is as follows:

Public void testquery1 (){ Session session = NULL; Try { Session = hibernateutils. getsession (); Session. begintransaction (); Query query = session. createquery ("from user "); // Query by PAGE Query. setfirstresult (0); // from which record the query starts, which is calculated from 0 Query. setmaxresults (2); // number of records displayed per page. /* * The query object has a list () method, which automatically generates List objects for all queried objects and returns them. */ List userlist = query. List (); // Then we can display the data. For (iterator iter = userlist. iterator (); ITER. hasnext ();){ User user = (User) ITER. Next (); System. Out. Print (user. GETID () + ""); System. Out. println (user. getname ()); } Session. gettransaction (). Commit (); } Catch (hibernateexception e ){ E. printstacktrace (); Session. gettransaction (). rollback (); } Finally { Hibernateutils. closesession (session ); } }

 

005 --- preliminary query interface