Hibernate conditional query in several ways + query all records

Conditional query

1, the first kind, with? Placeholders, such as://login (with the? placeholder)  PublicList<userpo> Loginuser (Userpo up)throwsexception{Session Session=hibernatesessionfactory.getsession (); String hql= "from Userpo where name =?" and pwd=? "; Query Query=session.createquery (HQL); Query.setstring (0, Up.getname ()); Query.setstring (1, Up.getpwd ()); List<UserPO> list =query.list ();  Session.close (); returnlist;}2, with ": +named "placeholders, such as://Login (with ": Name" placeholder)  PublicList<userpo> LoginUser2 (Userpo up)throwsexception{Session Session=hibernatesessionfactory.getsession (); String hql= "from Userpo where name =: N and pwd=:p"; Query Query=session.createquery (HQL); Query.setstring (N, Up.getname ()); Query.setstring ("P", Up.getpwd ()); List<UserPO> list =query.list ();  Session.close (); returnlist;} 2.1, you can also use this placeholder to set values such as://Login (with ": Name" placeholder, set value with Setparameter)  PublicList<userpo> LoginUser3 (Userpo up)throwsexception{Session Session=hibernatesessionfactory.getsession (); String hql= "from Userpo where name =: N and pwd=:p"; Query Query=session.createquery (HQL); Query.setparameter (N, Up.getname ()); Query.setparameter ("P", Up.getpwd ()); List<UserPO> list =query.list ();  Session.close (); returnlist;} Using this method does not need to state the type of mapping, Hibernate will automatically go through the configuration, but since Hibernate has two date formats: Date and timestamp, you must specify the type of the mapping for the date type. Wording:3, parameter binding according to the object, such as://Login (with ": Name" placeholder, set the value with SetProperties, the name parameter must be the same as the property name being bound)  PublicList<userpo> LoginUser4 (Userpo up)throwsexception{Session Session=hibernatesessionfactory.getsession (); String hql= "from Userpo where name =: Name and pwd=:p WD"; Query Query=session.createquery (HQL);  Query.setproperties (UP); List<UserPO> list =query.list ();  Session.close (); returnlist;}4, use condition query (criteria), such as://Sign In (conditional query criteria) completely out of SQL statements and HQL statements  PublicList<userpo> LoginUser5 (Userpo up)throwsexception{Session Session=hibernatesessionfactory.getsession (); Criteria CRI= Session.createcriteria (Userpo.class); Cri.add (Restrictions.eq ("Name", Up.getname ())); Cri.add (Restrictions.eq ("PWD", Up.getpwd ())); List<UserPO> list =cri.list ();  Session.close (); returnlist;} 5, offline conditional queries, such as://Login (query Detachedcriteria with offline conditions)  PublicList<userpo> LoginUser6 (Userpo up)throwsexception{Session Session=hibernatesessionfactory.getsession (); Detachedcriteria DC= Detachedcriteria.forclass (Userpo.class); Dc.add (Restrictions.eq ("Name", Up.getname ())); Dc.add (Restrictions.eq ("PWD", Up.getpwd ())); Criteria CRI=Dc.getexecutablecriteria (session); List<UserPO> list =cri.list ();  Session.close (); returnlist;} Using offline you can write it in the business layer and pass it in as a parameter to reduce the DAO's code. 6, paged query: The paging query is the processing method in the database application, and the query and Criteria interfaces provide a method for paging queries:1) Setfirstresult (int): Specifies which object to start the query from, and the parameter is the index position, starting at 0. 2) Setmaxresult (int): Specifies the maximum number of objects to query at one time.

Query all records:

/*** Check all the records*/  Public StaticList SelectAll () {List List=NULL; Try{Session=hibernatesessionfactory.getsession (); Transaction Tran=session.begintransaction (); Query Q= Session.createquery ("From User1"); List=q.list ();  Tran.commit (); } Catch(Exception e) {e.printstacktrace (); } finally{hibernatesessionfactory.closesession (); }  returnlist;} 

Hibernate conditional query in several ways + query all records