Dear All,

I am using hibernate SchemaExport to generate the create, drop and alter scripts but I am not getting the alter table scripts. Below are the files I am using to generate the DDL script.



Employee.java
--------------
@Entity
@Table(name = "EMPLOYEE")
public class Employee implements java.io.Serializable {

private static final long serialVersionUID = 1L;

private long empId;
private String empName;
private boolean manager;

public Employee() {
}

public Employee(String empName) {
this.empName = empName;
}

@Id
@GeneratedValue
@Column(name = "EMP_ID")
public long getEmpId() {
return this.empId;
}

public void setEmpId(long empId) {
this.empId = empId;
}

@Column(name = "EMP_NAME", nullable = false, length = 100)
public String getEmpName() {
return this.empName;
}

public void setEmpName(String empName) {
this.empName = empName;
}

@Column(name = "MANAGER", nullable = false, length = 1)
@org.hibernate.annotations.Check(constraints = "manager=true")
public boolean isManager() {
return manager;
}

public void setManager(boolean manager) {
this.manager = manager;
}


}


hibernate.cfg.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 name="">
<property name="hibernate.connection.driver_class">oracle.jdbc.driver.OracleDriver</property>
<property name="hibernate.connection.url">jdbc:oracle:thin:@172.25.108.238:1521:dlangebotsys</property>
<property name="hibernate.connection.username">dlangebot</property>
<property name="hibernate.connection.password">dlangebot</property>
<property name="hibernate.connection.pool_size">10</property>
<property name="show_sql">true</property>
<property name="dialect">org.hibernate.dialect.Oracle9Dialect</property>
<!-- <property name="hibernate.hbm2ddl.create">update</property> -->
<property name="hibernate.hbm2ddl.auto">create-update</property>
<!-- <property name="hibernate.hbm2ddl.auto">update</property> -->
<!-- Mapping files -->
<mapping class="com.hw.Employee" />
</session-factory>
</hibernate-configuration>


HibernateUtil.java
-------------------
public class HibernateUtil {

private static final SessionFactory sessionFactory;

static {
try {
File file = new File("D:/DdlQueryFile.sql");
if (!file.exists()) {
file.createNewFile();
System.out.println("File Created");
}

AnnotationConfiguration annotationConfiguration = new AnnotationConfiguration();
annotationConfiguration = annotationConfiguration.configure();
SchemaExport schemaExport = new SchemaExport(
annotationConfiguration);
schemaExport.setOutputFile("D:/" + file.getName()); /*
* Exports the
* script to the
* given file
*/
schemaExport.setFormat(true); /* Formats the created script */
schemaExport.setDelimiter(";"); /*
* Adds delimeter after every DDL
* script
*/
schemaExport.execute(true /* script */, true /* export to db */,
false /* just drop */, true /* just create */);

@SuppressWarnings("unchecked")
List<HibernateException> schemaExportExceptionList = schemaExport
.getExceptions();
if (schemaExportExceptionList != null) {
for (Iterator<HibernateException> iterator = schemaExportExceptionList
.iterator(); iterator.hasNext();) {
HibernateException hibernateException = iterator.next();
hibernateException.printStackTrace();
}
}
sessionFactory = annotationConfiguration.buildSessionFactory();

} catch (Throwable ex) {
System.err.println("Initial SessionFactory creation failed." + ex);
throw new ExceptionInInitializerError(ex);
}
}

public static SessionFactory getSessionFactory() {
return sessionFactory;
}
}


Generated Script
----------------
create table EMPLOYEE (
EMP_ID number(19,0) not null,
EMP_NAME varchar2(100 char) not null,
MANAGER number(1,0) not null,
primary key (EMP_ID)
);


Desired
--------
If table is existing in database and corresponding mapping file is changed (Employee.java in our case) I want only a alter table script should be generated adding the new column (empAdd in our case).

PROBLEM
--------
When I am adding the below code to Employee.java and executing it.

private String empAdd;

@Column(name = "EMP_ADD", nullable = false, length = 100)
public String getEmpAdd() {
return empAdd;
}

public void setEmpAdd(String empAdd) {
this.empAdd = empAdd;
}

Instead of generating alter script for the existing employee table it is throwing the following exception.

create table EMPLOYEE (
EMP_ID number(19,0) not null,
EMP_ADD varchar2(100 char) not null,
EMP_NAME varchar2(100 char) not null,
MANAGER number(1,0) not null,
primary key (EMP_ID)
);
Apr 27, 2011 10:21:10 AM org.hibernate.tool.hbm2ddl.SchemaExport create
SEVERE: Unsuccessful: create table EMPLOYEE (EMP_ID number(19,0) not null, EMP_ADD varchar2(100 char) not null, EMP_NAME varchar2(100 char) not null, MANAGER number(1,0) not null, primary key (EMP_ID))
Apr 27, 2011 10:21:10 AM org.hibernate.tool.hbm2ddl.SchemaExport create
SEVERE: ORA-00955: name is already used by an existing object


Could you please let me know where am I making mistake or kindly guide me to achieve the same.