Entity写法

@Entity
@Table(name = "bid")
public class ProxyBidEntity {

@Id
@GeneratedValue(strategy = GenerationType.AUTO)
private int id;

//竞拍品
@ManyToOne(cascade = CascadeType.MERGE)
@JoinColumn(name = "auction_item")
private AuctionItemEntity auctionItem;

@Column(name = "create_time")
private Date createTime;

//在线 Online， 代理Proxy
@Column(name = "source")
private Source source;

public enum Source implements StringValuedEnum { //枚举
ONLINE("在线"), PROXY("代理");

private String value;
Source(String value) {
this.value = value;
}
@Override
public String getValue() {
return value;
}

//修改标识， 防止同时修改。

@Version
@Temporal(TemporalType.TIMESTAMP)
@Column(name = "last_modified", nullable=false)
private Date lastModified;

}