title: Hibernate creates column without name when using "default CURRENT_TIMESTAMP on update CURRENT_TIMESTAMP"
body: <p>i got the following entity:</p>
  
  <pre><code>@Entity
  public class Person {
  
  @Id
  @GeneratedValue(strategy=GenerationType.AUTO)
  @Column(columnDefinition="int(11)",nullable=false)
  private int id;
  
  @Column(columnDefinition="varchar(255)",nullable=false)
  private String name;
  
  @Column(columnDefinition="varchar(255)",nullable=false)
  private String vorname;
  
  @Column(columnDefinition="varchar(255)",nullable=false)
  private String password;
  
  @Column(columnDefinition="varchar(100)",nullable=false)
  private String user;
  
  @Column(columnDefinition="varchar(20)",nullable=false)
  private String klasse;
  
  @Temporal(TemporalType.TIMESTAMP)
  @Column(name="timestamp",nullable = false,columnDefinition="default CURRENT_TIMESTAMP on update CURRENT_TIMESTAMP")
  private Date timestamp = new Date();
  
  
  public Person(){
  
  }
  @PreUpdate
  public void updatePerson(){
      this.timestamp = new Date();
  }
  
  
  ...getters
      ...setters
  </code></pre>
  
  <p>}</p>
  
  <p>When invoking hibenate , i get an error when hibernate wants to create the table. it seems the errror occurs, beacause the column timestamp has no name:</p>
  
  <p>ERROR: HHH000389: Unsuccessful: create table Person (id int(11) not null auto_increment, klasse varchar(20) not null, name varchar(255) not null, password varchar(255) not null, timestamp default CURRENT_TIMESTAMP on update CURRENT_TIMESTAMP not null, user varchar(100) not null, vorname varchar(255) not null, primary key (id)) type=MyISAM</p>
  
  <p>Does anyone knows why hibernate does this ?</p>