Hibernate (Object-Oriented Database Operations)

Hibernate (Object-Oriented Database Operations)
JPA, java persistance api, java persistence layer interface, that is, some interfaces dealing with databases. The implementation is handed over to various vendors for implementation.

ORM, Object/Relation Mapping, Object/Relational Database ing. For object-oriented database operations, the underlying layer is still SQL statements.

Obtain the maven dependency of hibernate.

 
  
   
Org. hibernate
  Hibernate-core
  
   
4.3.10.Final
  
 
 
       
  
   
Mysql
  Mysql-connector-java      
  
   
5.1.31
    
   

Hibernate is an excellent ORM implementation. For usage instructions, see.
The configuration file name is hibernate. cfg. xml, which is usually placed in the src directory. It uses c3p0 as the database connection pool.

  
 
  
  
   
    
Com. mysql. jdbc. Driver
   
   
    
Jdbc: mysql: //me.likeyichu.com: 3306/AliyunDB
   
   
    
True
   
   
    
UTF-8
   
   
    
Root
   
   
    
Password
   
   
   
    
20
   
   
    
1
   
   
    
5000
   
   
    
100
   
   
    
3000
   
   
    
True
   
   
    
2
   
   
   
    
True
   
   
   
    
Org. hibernate. dialect. MySQLDialect
   
   
   
  
     

Common classes @ javax. persistence. Entity
Indicates that this class corresponds to an object in a table in the database.
@ Javax. persistence. Table
The name attribute of this annotation indicates which table the java class corresponds.


@ Javax. persistence. Id
Indicate that this field is the primary key in the database table.
@ Javax. persistence. Column
The name attribute of this annotation specifies which column of the field corresponds to the table. By default, mutual matching of the same name is performed.
@ Javax. persistence. Temporal
The database has many time types. The value TemporalType. TIMESTAMP indicates the TIMESTAMP.
@ Javax. persistence. Transient
When a pojo field is not in the table, you can add this comment to avoid errors.

HQLorg. hibernate. SharedSessionContract. createQuery (String queryString)
Create a query using the given hql statement.
List org. hibernate. Query. list ()
Returns the query result as a list.
Sample Code

Package com. likeyichu. webservice. resource. me; import java. SQL. timestamp; import java. util. date; import java. util. list; import javax. persistence. column; import javax. persistence. entity; import javax. persistence. id; import javax. persistence. table; import javax. persistence. temporal; import javax. persistence. temporalType; import org. hibernate. session; import org. hibernate. sessionFactory; import org. hibernate. trans Action; import org. hibernate. cfg. configuration; import org. hibernate. service. serviceRegistry; import org. hibernate. service. serviceRegistryBuilder; @ Entity @ Table (name = "studentTable") public class Student {@ Idint id; String name; boolean isGirl; @ Column (name = "time_stamp ") @ Temporal (TemporalType. TIMESTAMP) Date timestamp; public int getId () {return id;} public void setId (int id) {this. id = id;} public Date get TimeStamp () {return timestamp;} public void setTimeStamp (Date timeStamp) {this. timestamp = timeStamp;} public String getName () {return name;} public void setName (String name) {this. name = name;} public boolean isGirl () {return isGirl;} public void setGirl (boolean isGirl) {this. isGirl = isGirl;} public static void main (String [] args) {// load src/hibernate. cfg. xml as Configuration conf = new Configuration (). co Nfigure (); // so long, annoyingServiceRegistry serviceRegistry = new ServiceRegistryBuilder (). applySettings (conf. getProperties ()). buildServiceRegistry (); SessionFactory sf = conf. buildSessionFactory (serviceRegistry); Session sess = sf. openSession (); Transaction ts = sess. beginTransaction (); Student student = new Student (); student. setName ("qiqi"); // Add a data sess row. save (student); ts. commit (); // obtain all female students and assemble them into a list. @ SuppressWarnings ("unchecked") List <Student> list = sess. createQuery ("from Student where isGirl = true "). list (); System. out. println (list); sess. close (); sf. close ();}}