import java.io.Serializable;

import javax.persistence.CascadeType;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.ManyToOne;
import javax.persistence.Table;

@Entity
@Table(name="EMPLOYEE")
public class Employee implements Serializable {

    /**
     *
     */
    private static final long serialVersionUID = 1L;

    @Id
    @Column(name="ID", nullable = false)
    @GeneratedValue(strategy = GenerationType.AUTO)
    private int id;

    @Column(name="FIRST_NAME", nullable = false)
    private String firstName;

    @Column(name="LAST_NAME", nullable = false)
    private String lastName;

    @Column(name="USERNAME", nullable = false)
    private String userName;

    @Column(name="PASSWORD", nullable = false)
    private String password;

    @Column(name="EMAIL", nullable = false)
    private String email;

    @Column(name="AGE", nullable = true)
    private int age;

    @Column(name="ROLE", nullable = true)
    private Role role;

    public String getFirstName() {
        return firstName;
    }
    public void setFirstName(String firstName) {
        this.firstName = firstName;
    }
    public String getLastName() {
        return lastName;
    }
    public void setLastName(String lastName) {
        this.lastName = lastName;
    }
    public String getEmail() {
        return email;
    }
    public void setEmail(String email) {
        this.email = email;
    }
    public int getId() {
        return id;
    }
    public void setId(int id) {
        this.id = id;
    }
    public String getUserName() {
        return userName;
    }
    public void setUserName(String userName) {
        this.userName = userName;
    }
    public String getPassword() {
        return password;
    }
    public void setPassword(String password) {
        this.password = password;
    }

    @ManyToOne
    @JoinColumn(name="role",referencedColumnName="ROLE_ID")
    public Role getRole() {
        return role;
    }
    public void setRole(Role role) {
        this.role = role;
    }
    public int getAge() {
        return age;
    }
    public void setAge(int age) {
        this.age = age;
    }

    @Override
    public String toString() {
        // TODO Auto-generated method stub
        return this.getFirstName() + " " + this.getLastName() + " " + this.getEmail() + " " + this.getAge();
    }
}

import java.io.Serializable;
import java.util.List;

import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.Id;
import javax.persistence.OneToMany;
import javax.persistence.Table;

@Entity
@Table(name = "ROLE")
public class Role implements Serializable {

    @Id
    @Column(name="ROLE_ID", nullable = false, unique = true)
    private int roleId;

    @Column(name="ROLE", nullable = false)
    private String role;


    public int getRoleId() {
        return roleId;
    }

    public void setRoleId(int roleId) {
        this.roleId = roleId;
    }

    public String getRole() {
        return role;
    }

    public void setRole(String role) {
        this.role = role;
    }

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Scope;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.validation.BindingResult;
import org.springframework.web.bind.annotation.ModelAttribute;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.SessionAttributes;
import org.springframework.web.bind.support.SessionStatus;

import com.techm.spring.model.Employee;
import com.techm.spring.service.EmployeeService;
import com.techm.spring.service.RoleService;

@Controller
@RequestMapping("/employee/new")
@Scope("request")
@SessionAttributes("employee") //This will save the employee model attribute in session
public class EmployeeController {

    @Autowired
    public EmployeeService employeeService;

    @Autowired
    public RoleService roleService;

    @RequestMapping(value="/registration", method = RequestMethod.GET)
    public String setUpSignUpForm(Model model) {

        Employee emp = new Employee();
        model.addAttribute("employee",emp);

        //populating roles to show on sign up form
        model.addAttribute("roles",roleService.getRoles());

        return "signUp";
    }

    @RequestMapping(value="/registration",method = RequestMethod.POST)
    public String addNewEmployee(@ModelAttribute("employee") Employee emp, BindingResult result, SessionStatus status) {

        //status.setComplete(); This will clear the session
        System.out.println(emp.getRole().getRoleId());

        employeeService.addEmployee(emp);
        return "redirect:success";
    }

    @RequestMapping(value = "/success", method = RequestMethod.GET)
    public String success() {

        return "registrationSuccessPage";
    }

    @ModelAttribute("employee")
    public Employee getEmployee() {
        return new Employee();

    }
}

<%@ page language="java" contentType="text/html; charset=ISO-8859-1" pageEncoding="ISO-8859-1"%>
<%@ taglib prefix="form" uri="http://www.springframework.org/tags/form"%>
<%@ taglib prefix="spring" uri="http://www.springframework.org/tags" %>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<%@ taglib prefix="fmt" uri="http://java.sun.com/jsp/jstl/fmt" %>
<%@ taglib prefix="fn" uri="http://java.sun.com/jsp/jstl/functions" %>
<%@ page isELIgnored="false" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>Spring 4 MVC - HelloWorld Sign Up Page</title>
    <title>Add Employee Form</title>

    <style>
    .error
    {
        color: #ff0000;
        font-weight: bold;
    }
    </style>
</head>
<body>

<p style="color:green; font-weight: bold;">Sign Up</p>
<form:form method="post" modelAttribute="employee" action="registration">

<table>
    <tr>
        <td>First Name:</td>
        <td><form:input path="firstName" /></td>
    </tr>
    <tr>
        <td>Last Name:</td>
        <td><form:input path="lastName" /></td>
    </tr>
    <tr>
        <td>Email:</td>
        <td><form:input path="email" /></td>
    </tr>
    <tr>
        <td>UserName:</td>
        <td><form:input path="userName" /></td>
    </tr>
    <tr>
        <td>Password:</td>
        <td><form:password path="password" /></td>
    </tr>
    <tr>
        <td>Role:</td>
        <td>
            <form:select path="role.roleId">
                <form:option value="-1">Select Role</form:option>
                <form:options items="${roles}" itemLabel="role" itemValue="roleId"/>
            </form:select>
        </td>
    </tr>
    <tr>
        <td>Age:</td>
        <td><form:input path="age"/></td>
    </tr>
    <tr>
        <td colspan="3"><input type="submit" value="Sign Up"/></td>
    </tr>
</table>

</form:form>


</body>
</html>

Hibernate: insert into EMPLOYEE (AGE, EMAIL, FIRST_NAME, LAST_NAME, PASSWORD, ROLE, USERNAME, ID) values (?, ?, ?, ?, ?, ?, ?, ?)
Oct 18, 2016 7:53:52 PM org.hibernate.engine.jdbc.spi.SqlExceptionHelper logExceptions
WARN: SQL Error: 932, SQLState: 42000
Oct 18, 2016 7:53:52 PM org.hibernate.engine.jdbc.spi.SqlExceptionHelper logExceptions
ERROR: ORA-00932: inconsistent datatypes: expected NUMBER got BINARY

Oct 18, 2016 7:53:52 PM org.hibernate.engine.jdbc.batch.internal.AbstractBatchImpl release
INFO: HHH000010: On release of batch it still contained JDBC statements
Oct 18, 2016 7:53:52 PM org.apache.catalina.core.StandardWrapperValve invoke
SEVERE: Servlet.service() for servlet [dispatcher] in context with path [/SpringMVC] threw exception [Request processing failed; nested exception is org.springframework.dao.InvalidDataAccessResourceUsageException: could not execute statement; SQL [n/a]; nested exception is org.hibernate.exception.SQLGrammarException: could not execute statement] with root cause
java.sql.SQLSyntaxErrorException: ORA-00932: inconsistent datatypes: expected NUMBER got BINARY

    at oracle.jdbc.driver.T4CTTIoer.processError(T4CTTIoer.java:445)
    at oracle.jdbc.driver.T4CTTIoer.processError(T4CTTIoer.java:396)
    at oracle.jdbc.driver.T4C8Oall.processError(T4C8Oall.java:879)
    at oracle.jdbc.driver.T4CTTIfun.receive(T4CTTIfun.java:450)
    at oracle.jdbc.driver.T4CTTIfun.doRPC(T4CTTIfun.java:192)
    at oracle.jdbc.driver.T4C8Oall.doOALL(T4C8Oall.java:531)
    at oracle.jdbc.driver.T4CPreparedStatement.doOall8(T4CPreparedStatement.java:207)
    at oracle.jdbc.driver.T4CPreparedStatement.executeForRows(T4CPreparedStatement.java:1044)
    at oracle.jdbc.driver.OracleStatement.doExecuteWithTimeout(OracleStatement.java:1329)
    at oracle.jdbc.driver.OraclePreparedStatement.executeInternal(OraclePreparedStatement.java:3584)
    at oracle.jdbc.driver.OraclePreparedStatement.executeUpdate(OraclePreparedStatement.java:3665)
    at oracle.jdbc.driver.OraclePreparedStatementWrapper.executeUpdate(OraclePreparedStatementWrapper.java:1352)
    at org.hibernate.engine.jdbc.internal.ResultSetReturnImpl.executeUpdate(ResultSetReturnImpl.java:208)
    at org.hibernate.engine.jdbc.batch.internal.NonBatchingBatch.addToBatch(NonBatchingBatch.java:62)
    at org.hibernate.persister.entity.AbstractEntityPersister.insert(AbstractEntityPersister.java:3124)
    at org.hibernate.persister.entity.AbstractEntityPersister.insert(AbstractEntityPersister.java:3581)
    at org.hibernate.action.internal.EntityInsertAction.execute(EntityInsertAction.java:104)
    at org.hibernate.engine.spi.ActionQueue.executeActions(ActionQueue.java:465)
    at org.hibernate.engine.spi.ActionQueue.executeActions(ActionQueue.java:351)
    at org.hibernate.event.internal.AbstractFlushingEventListener.performExecutions(AbstractFlushingEventListener.java:350)
    at org.hibernate.event.internal.DefaultFlushEventListener.onFlush(DefaultFlushEventListener.java:56)
    at org.hibernate.internal.SessionImpl.flush(SessionImpl.java:1258)
    at org.hibernate.internal.SessionImpl.managedFlush(SessionImpl.java:425)
    at org.hibernate.engine.transaction.internal.jdbc.JdbcTransaction.beforeTransactionCommit(JdbcTransaction.java:101)
    at org.hibernate.engine.transaction.spi.AbstractTransactionImpl.commit(AbstractTransactionImpl.java:177)
    at org.springframework.orm.hibernate4.HibernateTransactionManager.doCommit(HibernateTransactionManager.java:584)
    at org.springframework.transaction.support.AbstractPlatformTransactionManager.processCommit(AbstractPlatformTransactionManager.java:761)
    at org.springframework.transaction.support.AbstractPlatformTransactionManager.commit(AbstractPlatformTransactionManager.java:730)
    at org.springframework.transaction.interceptor.TransactionAspectSupport.commitTransactionAfterReturning(TransactionAspectSupport.java:485)
    at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:291)
    at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:96)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
    at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:208)
    at $Proxy63.addEmployee(Unknown Source)
    at com.techm.spring.service.EmployeeServiceImpl.addEmployee(EmployeeServiceImpl.java:18)
    at com.techm.spring.controller.EmployeeController.addNewEmployee(EmployeeController.java:48)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    at java.lang.reflect.Method.invoke(Unknown Source)
    at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:222)
    at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:137)
    at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:110)
    at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:814)
    at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:737)
    at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:85)
    at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:959)
    at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:893)
    at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:969)
    at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:871)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:641)
    at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:845)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:304)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:240)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:164)
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:462)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:164)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:100)
    at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:562)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:395)
    at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:250)
    at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:188)
    at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:302)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
    at java.lang.Thread.run(Unknown Source)