数据的安插和更新时间

数据的插入和更新时间

最近项目要求某些表记录数据的插入时间和更新时间：

import java.util.Date;import javax.persistence.Column;import javax.persistence.Entity;import javax.persistence.GeneratedValue;import javax.persistence.Id;import javax.persistence.ManyToOne;@Entitypublic class Wangwang {    private Integer id;   private User owner;   private boolean deleted;        private Date createdTime = new Date();    private Date updatedTime;    @Id    @GeneratedValue    public Integer getId() {        return id;    }    public void setId(Integer id) {        this.id = id;    }    @ManyToOne    public User getOwner() {        return owner;    }    public void setOwner(User owner) {        this.owner = owner;    }    @Column(nullable = false)    public boolean isDeleted() {        return deleted;    }    public void setDeleted(boolean deleted) {        this.deleted = deleted;    }    @Column(updatable=false)    public Date getCreatedTime() {        return createdTime;    }    public void setCreatedTime(Date createdTime) {        this.createdTime = createdTime;    }    @Column(columnDefinition="TIMESTAMP NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP", updatable=false)    public Date getUpdatedTime() {        return updatedTime;    }    public void setUpdatedTime(Date updatedTime) {        this.updatedTime = updatedTime;    }}

?createdTime记录插入数据的时间，updatedTime记录更新数据的时间。要注意@Column注解的updatable=false，否则更新数据时，时间戳会先被MySQL修改为当前时间，然后Hibernate的更新语句会把时间改回原来的值。

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利用MySQL的触发器也可实现此功能： http://lanhuidong.iteye.com/blog/765134