Hi,

I have written a sample hibernate program.

Hibernate version: 3.3.1

Mapping documents:
<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC
"-//Hibernate/Hibernate Mapping DTD//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd" >

<hibernate-mapping package="com">
<class
name="Test"
table="TEST"
>
<meta attribute="sync-DAO">false</meta>

<id name="id" column="ID" type="java.lang.Long">
<generator class="native"/>
</id>

<property
name="name"
column="NAME"
type="string"
not-null="false"
length="20"
/>
<property
name="mdt"
column="MDT"
type="java.lang.String"
not-null="false"
length="11"
/>
</class>
</hibernate-mapping>



mapping class file:

package com.base;

import java.io.Serializable;


/**
* This is an object that contains data related to the TEST table.
* Do not modify this class because it will be overwritten if the configuration file
* related to this class is modified.
*
* @hibernate.class
* table="TEST"
*/

public abstract class BaseTest implements Serializable {

public static String REF = "Test";
public static String PROP_NAME = "name";
public static String PROP_ID = "id";
public static String PROP_MDT = "mdt";


// constructors
public BaseTest () {
initialize();
}

/**
* Constructor for primary key
*/
public BaseTest (java.lang.Long id) {
this.setId(id);
initialize();
}

protected void initialize () {}



private int hashCode = Integer.MIN_VALUE;

// primary key
private java.lang.Long id;

// fields
private java.lang.String name;
private java.lang.String mdt;



/**
* Return the unique identifier of this class
* @hibernate.id
* generator-class="native"
* column="ID"
*/
public java.lang.Long getId () {
return id;
}

/**
* Set the unique identifier of this class
* @param id the new ID
*/
public void setId (java.lang.Long id) {
this.id = id;
this.hashCode = Integer.MIN_VALUE;
}




/**
* Return the value associated with the column: NAME
*/
public java.lang.String getName () {
return name;
}

/**
* Set the value related to the column: NAME
* @param name the NAME value
*/
public void setName (java.lang.String name) {
this.name = name;
}



/**
* Return the value associated with the column: MDT
*/
public java.lang.String getMdt () {
return mdt;
}

/**
* Set the value related to the column: MDT
* @param mdt the MDT value
*/
public void setMdt (java.lang.String mdt) {
this.mdt = mdt;
}




public boolean equals (Object obj) {
if (null == obj) return false;
if (!(obj instanceof com.Test)) return false;
else {
com.Test test = (com.Test) obj;
if (null == this.getId() || null == test.getId()) return false;
else return (this.getId().equals(test.getId()));
}
}

public int hashCode () {
if (Integer.MIN_VALUE == this.hashCode) {
if (null == this.getId()) return super.hashCode();
else {
String hashStr = this.getClass().getName() + ":" + this.getId().hashCode();
this.hashCode = hashStr.hashCode();
}
}
return this.hashCode;
}


public String toString () {
return super.toString();
}


}


Code between sessionFactory.openSession() and session.close():
Test t = new Test();
sess.save(t);




hibernate config xml

<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE hibernate-configuration
PUBLIC "-//Hibernate/Hibernate Configuration DTD//EN"
"http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">

<hibernate-configuration>
<session-factory>

<!-- local connection properties -->
<property name="hibernate.connection.url">jdbc:oracle:thin:@localhost:1521:xe</property>
<property name="hibernate.connection.driver_class">oracle.jdbc.driver.OracleDriver</property>
<property name="hibernate.connection.username">portal</property>
<property name="hibernate.connection.password">portal</property>
<!-- property name="hibernate.connection.pool_size"></property -->

<!-- dialect for Oracle -->
<property name="dialect">org.hibernate.dialect.Oracle10gDialect</property>

<property name="hibernate.show_sql">true</property>
<property name="hibernate.transaction.factory_class">org.hibernate.transaction.JDBCTransactionFactory</property>

<mapping resource="Test.hbm.xml"/>

</session-factory>
</hibernate-configuration>



Full stack trace of any exception that occurs:
Hibernate: select hibernate_sequence.nextval from dual
helloorg.hibernate.exception.SQLGrammarException: could not get next sequence value
5256 [main] WARN org.hibernate.util.JDBCExceptionReporter - SQL Error: 2289, SQLState: 42000
5256 [main] ERROR org.hibernate.util.JDBCExceptionReporter - ORA-02289: sequence does not exist


Name and version of the database you are using: Oracle 10g

Please help me in resolving this issue.

Thanks,
Sri

Did you read the error message and check the Oracle documentation?

Try this: Using SQL*Plus, login into the account PORTAL on the database XE and enter the following command:

CREATE SEQUENCE HIBERNATE_SEQUENCE;

Thanks.

I can create a sequence in the database, but I have given the id generator as native, so that I can decouple my code from db specific.

So I am wondering, what would be the solution for this problem?

Thanks,
Sri

What makes you think there is a problem? If you check the Hibernate reference document, section 5.1.4.1, it states:



Since Oracle doesn't have identity columns (at least, it didn't the last time I looked), then Hibernate must choose one of the latter two options. Looking at the source code, it appears that the Dialect code checks the options in the same order as the documentation -- identity, sequence, and then hilo. So, when using Oracle, Hibernate is going to use a sequence.

If you move your code to another database engine that does support identity columns, it will use those.