Hibernate Mapping

A mapping example using xml

<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE hibernate-mapping PUBLIC 
 "-//Hibernate/Hibernate Mapping DTD//EN"
 "http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd"> 

<hibernate-mapping>
   <class name="Employee" table="EMPLOYEE">
      <meta attribute="class-description">
         This class contains the employee detail. 
      </meta>
      <id name="id" type="int" column="id">
         <generator class="native"/>
      </id>
      <property name="firstName" column="first_name" type="string"/>
      <property name="lastName" column="last_name" type="string"/>
      <property name="salary" column="salary" type="int"/>
   </class>
</hibernate-mapping>

The file name should be .hbm.xml

Mapping type

Primitive types

Mapping Type	Java Type	ANSI SQL type
integer	int/java.lang.Integer	INTEGER
long	long/java.lang.Long	BIGINT
short	short/java.lang.Short	SMALLINT
float	float/java.lang.Float	FLOAT
double	double/java.lang.Double	DOUBLE
big_decimal	java.math.BigDecimal	NUMERIC
character	java.lang.String	CHAR(1)
string	java.lang.String	VARCHAR
byte	byte/java.lang.Byte	TINYINT
boolean	boolean/java.lang.Boolean	BIT
yes/no	boolean/java.lang.Boolean	CHAR(1) (‘Y’ or ‘N’)
true/false	boolean/java.lang.Boolean	CHAR(1) (‘T’ or ‘F’)

Date types

Mapping Type	Java Type	ANSI SQL type
date	java.util.Date/java.sql.Date	DATE
time	java.util.Date/java.sql.Time	TIME
timestamp	java.util.Date/java.sql.Timestamp	TIMESTAMP
calendar	java.util.Calendar	TIMESTAMP
calendar_date	java.util.Calendar	DATE

Binary and BLOB types

Mapping Type	Java Type	ANSI SQL type
binary	byte[]	VARBINARY (or BLOB)
text	java.lang.String	CLOB
serializable	any Java class that implements java.io.Serializable	VARBINARY (or BLOB)
clob	java.sql.Clob	CLOB
blob	java.sql.Blob	BLOB

JDK arelated types

Mapping Type	Java Type	ANSI SQL type
class	java.lang.Class	VARCHAR
locale	java.util.Locale	VARCHAR
timezone	java.util.TimeZone	VARCHAR
currency	java.util.Currency	VARCHAR

Annotations

@Entity @Table @id @GeneratedValue @Column

An example

import javax.persistence.*;

@Entity
@Table(name = "EMPLOYEE")
public class Employee {
   @Id @GeneratedValue
   @Column(name = "id")
   private int id;

   @Column(name = "first_name")
   private String firstName;

   @Column(name = "last_name")
   private String lastName;

   @Column(name = "salary")
   private int salary;  

   public Employee() {}
   public int getId() {
      return id;
   }
   public void setId( int id ) {
      this.id = id;
   }
   public String getFirstName() {
      return firstName;
   }
   public void setFirstName( String first_name ) {
      this.firstName = first_name;
   }
   public String getLastName() {
      return lastName;
   }
   public void setLastName( String last_name ) {
      this.lastName = last_name;
   }
   public int getSalary() {
      return salary;
   }
   public void setSalary( int salary ) {
      this.salary = salary;
   }
}