Identity Algorithm

Identity algorithm is able to generate primary key values on the basis on the underlying database table provided identity column.

Note

Identity column is a primary key Column with “auto_increment” capability.

This algorithm is able to provide the primary key values of the data types like short, int, long, etc.
This algorithm is not required any input parameter.
This algorithm is supported by almost all the databases which are supporting Identity column.
- E.g MySQL.
To represent this algorithm, Hibernate has provided “identity” as short name and “org.hibernate.id.IdentityGenerator” as predefined class.

sql>create table emp(id primary key auto_increment, emp_name varchar2(30), salary float, address varchar2(20));

E.g

<?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="com.ashok.hibernate.sample.model.Employee" table="emp">
		<id name="id" type="int" column="id">
			<generator class="identity" />
		</id>
		<property name="empName" column="emp_name" type="string" />
		<property name="address" column="address" type="string" />
		<property name="salary" column="salary" type="float" />
	</class>
</hibernate-mapping>

Identity Algorithm