package com.im.sell.entity;

import lombok.Data;
import org.hibernate.annotations.DynamicUpdate;

import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import java.util.Date;

@Entity
@DynamicUpdate
@Data
public class ProductCategory {

@Id
@GeneratedValue
private Integer categoryId;
private String categoryName;
private Integer categoryType;

private Date createTime;
private Date updateTime;

public ProductCategory() {
}

public ProductCategory(String categoryName, Integer categoryType) {
    this.categoryName = categoryName;
    this.categoryType = categoryType;
}

public ProductCategory categoryName(String categoryName) {
    this.categoryName = categoryName;
    return this;
}

public ProductCategory categoryType(Integer categoryType) {
    this.categoryType = categoryType;
    return this;
}

}
@Test
public void testUpdate() {
ProductCategory category = new ProductCategory();
category.setCategoryName(“有机食品”);
category.setCategoryType(3);
category.setCategoryId(1);

 /*   ProductCategory productCategory = productCategoryDao.findOne(1);
    productCategory.setCategoryType(4);
    productCategory.setCategoryName("有机红茶");*/
    ProductCategory targetCategory = productCategoryDao.save(category);
    System.out.println(targetCategory.toString());
    Assert.assertNotNull(targetCategory);
}

数据库中有个categoryId为1，categoryType为2的记录，我自己构造一个类目对象，按照上面贴出的测试进行更新，发现数据库中的创建时间和更新时间 一起变化控制台打印出的SQL是这个样子的：Hibernate: update product_category set category_name=?, category_type=?, create_time=?, update_time=? where category_id=?，但是我从数据库中将这条数据查出来然后更新，就是可以的。很奇怪，不懂，请老师指点一下？