configuration of hibernate in xml

[Gajendra Kangokar]

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-configuration SYSTEM "http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">



<hibernate-configuration>
<session-factory>
		<property name="hibernate.dialect">org.hibernate.dialect.MySQLDialect</property>		
		<property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property>
		
		<property name="hibernate.connection.url">jdbc:mysql://localhost:3306/hbmtest</property>
		<property name="hibernate.connection.username">root</property>
		<property name="hibernate.connection.password">root</property>
		<!-- <property name="hbm2ddl.auto">create</property> -->
		
		<mapping resource="Employee.hbm.xml"></mapping>
</session-factory>
</hibernate-configuration>

Hi,

above is my xml configuration using JPA hibernate I have mapped my Entity class as well (Employee),
whenever I start hibernate, Employee table is newly created and i loose all data from the table which was stored last time.

I have also commented this line <!-- <property name="hbm2ddl.auto">create</property> -->.
please someome tell me where i am gone wrong,what is the solution.

Thank you
Gajendra

[Emil Jennings]

The configuration property hibernate.hbm2ddl.auto has four values:

validate: validate the schema, makes no changes to the database.
update: update the schema. Be very careful (read avoid) using update in production.
create: creates the schema, destroying previous data.
create-drop: drop the schema at the end of the session.