Mybatis的注解开发JPA和xml配置文件

1.注解配置

采用注解的方式将实体类与数据库表相对应，例如表面，列名，多对一的对应关系

@Entity
public class Product {
	// 主键ID
	@Id
	private Long productId;
	// 商品名
	private String productName;
	// 商品简介
	private String productDesc;
	// 简略图
	private String imgAddr;
	// 原价
	private String normalPrice;
	// 现价(推广价格)
	private String promotionPrice;
	// 权重，越大越排前显示
	private Integer priority;
	// 创建时间
	private Date createTime;
	// 最近一次的更新时间
	private Date lastEditTime;
	// 0.下架 1.在前端展示系统展示
	private Integer enableStatus;
 
	// 图片详情图列表，跟商品是多对一的关系
	//商品作为一方使用OneToMany注解
	@OneToMany                                          //指定一对多关系
	@Cascade(value={CascadeType.SAVE_UPDATE})           //设定级联关系
	@JoinColumn(name="productImgId")  
	private List<ProductImg> productImgList;
	// 商品类别，一件商品仅属于一个商品类别
	@ManyToOne()
	@JoinColumn(name = "productCategoryId")
	private ProductCategory productCategory;
	// 店铺实体类，标明商品属于哪个店铺
	@ManyToOne()
	@JoinColumn(name = "shop_id")
	private Shop shop;

2. 采用xml配置文件的方式

<mapper namespace="com.xxx.xxxx.ProductDao">
    <resultMap id="productMap" type="com.imooc.o2o.entity.Product">
        <id column="product_id" property="productId" />
        <result column="product_name" property="productName" />
        <result column="product_desc" property="productDesc" />
        <result column="img_addr" property="imgAddr" />
        <result column="normal_price" property="normalPrice" />
        <result column="promotion_price" property="promotionPrice" />
        <result column="priority" property="priority" />
        <result column="create_time" property="createTime" />
        <result column="last_edit_time" property="lastEditTime" />
        <result column="enable_status" property="enableStatus" />
        <association property="productCategory" column="product_category_id"
                     javaType="com.light.entity.ProductCategory">
            <id column="product_category_id" property="productCategoryId" />
            <result column="product_category_name" property="productCategoryName" />
        </association>
        <association property="shop" column="shop_id"
                     javaType="com.light.entity.Shop">
            <id column="shop_id" property="shopId" />
            <result column="owner_id" property="ownerId" />
            <result column="shop_name" property="shopName" />
        </association>
        <collection property="productImgList" column="product_id"
                    ofType="com.light.entity.ProductImg">
            <id column="product_img_id" property="productImgId" />
            <result column="detail_img" property="imgAddr" />
            <result column="img_desc" property="imgDesc" />
            <result column="priority" property="priority" />
            <result column="create_time" property="createTime" />
            <result column="product_id" property="productId" />
        </collection>
    </resultMap>