Unknown column Error when using ManyToOne annotation

[Harish Tiruvile]

Hi,

While executing Hibernate program i am getting below exception.I am unable to know the root cause for this issue.Please let me know how to correct this and what went wrong in below code.
Exception is

Hibernate: insert into CUST_NAME (Customer_Name) values (?)
Hibernate: insert into ORDERS_1 (configType, customerName_Customer_Id, srvType) values (?, ?, ?)
Exception in thread "main" org.hibernate.exception.SQLGrammarException: could not insert: [org.harish.javaprgs.CustomerOrder]
	at org.hibernate.exception.SQLStateConverter.convert(SQLStateConverter.java:92)
	at org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:66)
	at org.hibernate.id.insert.AbstractReturningDelegate.performInsert(AbstractReturningDelegate.java:64)
	at org.hibernate.persister.entity.AbstractEntityPersister.insert(AbstractEntityPersister.java:2345)
	at org.hibernate.persister.entity.AbstractEntityPersister.insert(AbstractEntityPersister.java:2852)
         ... . 
	at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
	at java.lang.reflect.Method.invoke(Unknown Source)
	at org.hibernate.context.ThreadLocalSessionContext$TransactionProtectionWrapper.invoke(ThreadLocalSessionContext.java:345)
	at $Proxy9.save(Unknown Source)
	at org.harish.javaprgs.TestUserDetails.main(TestUserDetails.java:23)
Caused by: com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: Unknown column 'customerName_Customer_Id' in 'field list'
	. . .  . 

@Entity(name = "CUST_NAME")
public class Customer {
	@Id
	@Column(name = "Customer_Id")
	@GeneratedValue(strategy = GenerationType.AUTO)
	private int cust_id;

	@Column(name = "Customer_Name")
	private String cust_name;

	@OneToMany(mappedBy="customerName")
	private Collection<CustomerOrder> order = new ArrayList<CustomerOrder>();

	public int getCust_id() {
		return cust_id;
	}

	public void setCust_id(int custId) {
		cust_id = custId;
	}

	public String getCust_name() {
		return cust_name;
	}

	public void setCust_name(String custName) {
		cust_name = custName;
	}

	public Collection<CustomerOrder> getOrder() {
		return order;
	}

	public void setOrder(Collection<CustomerOrder> order) {
		this.order = order;
	}

}

@Entity(name = "ORDERS_1")
public class CustomerOrder {
	@Id
	@GeneratedValue(strategy = GenerationType.AUTO)
	private int orderId;
	private String srvType;
	private String configType;
	
	@ManyToOne
	private Customer customerName;

	public Customer getCustomerName() {
		return customerName;
	}

	public void setCustomerName(Customer customerName) {
		this.customerName = customerName;
	}

	public String getConfigType() {
		return configType;
	}

	public void setConfigType(String configType) {
		this.configType = configType;
	}

	public int getOrderId() {
		return orderId;
	}

	public void setOrderId(int orderId) {
		this.orderId = orderId;
	}

	public String getSrvType() {
		return srvType;
	}

	public void setSrvType(String srvType) {
		this.srvType = srvType;
	}

}

public class TestUserDetails {

	public static void main(String[] args) {
		Customer u1 = new Customer();
		u1.setCust_name("Tata");

		CustomerOrder order1 = new CustomerOrder();
		order1.setSrvType("VPN");
		order1.setCustomerName(u1);
		u1.getOrder().add(order1);
		SessionFactory sf = new Configuration().configure()
				.buildSessionFactory();
		Session s = sf.getCurrentSession();
		Transaction tx = s.beginTransaction();
		s.save(u1);
		s.save(order1);
		tx.commit();

	}
}