Mybatis关联关系映射

目标
1、一对多关联关系
2、多对多关联关系

一对多

首先先用逆向生成工具生成t_hibernate_order、t_hibernate_order_item
这两张表对应的model与mapper

OrderVo

package com.cgl.ssm.model.vo;

import com.cgl.ssm.model.Order;
import com.cgl.ssm.model.OrderItem;

import java.util.ArrayList;
import java.util.List;

/**
 * @authorlyl
 * @site
 * @company
 * @create  2019-10-23 11:06
 */
public class OrderVo extends Order {
    private List<OrderItem> orderItems = new ArrayList();

    public List<OrderItem> getOrderItems() {
        return orderItems;
    }

    public void setOrderItems(List<OrderItem> orderItems) {
        this.orderItems = orderItems;
    }
}

OrderItemVo

package com.cgl.ssm.model.vo;

import com.cgl.ssm.model.Order;
import com.cgl.ssm.model.OrderItem;

/**
 * @authorlyl
 * @site
 * @company
 * @create  2019-10-23 11:07
 */
public class OrderItemVo extends OrderItem {
    private Order order;

    public Order getOrder() {
        return order;
    }

    public void setOrder(Order order) {
        this.order = order;
    }
}

OrderMapper.xml

<resultMap id="OrderVoMap" type="com.cgl.ssm.model.vo.OrderVo">
    <result property="orderId" column="order_id"></result>
    <result property="orderNo" column="order_no"></result>
    <!--<result property="orderItems"></result>-->
    <collection property="orderItems" ofType="com.cgl.ssm.model.OrderItem">
      <result property="orderItemId" column="order_item_id"></result>
      <result property="productId" column="product_id"></result>
      <result property="quantity" column="quantity"></result>
      <result property="oid" column="oid"></result>
    </collection>
  </resultMap>
  
 <select id="selectByOrderId" resultMap="OrderVoMap" parameterType="java.lang.Integer" >
    select * from t_hibernate_order o,t_hibernate_order_item oi where o.order_id=oi.oid and oi.oid = #{orderId}
  </select>

OrderMapper.java

package com.cgl.ssm.mapper;

import com.cgl.ssm.model.Order;
import com.cgl.ssm.model.vo.OrderVo;
import org.apache.ibatis.annotations.Param;
import org.springframework.stereotype.Repository;

import java.util.List;

@Repository

public interface OrderMapper {
    int deleteByPrimaryKey(Integer orderId);

    int insert(Order record);

    int insertSelective(Order record);

    Order selectByPrimaryKey(Integer orderId);

    int updateByPrimaryKeySelective(Order record);

    int updateByPrimaryKey(Order record);

    List<OrderVo> selectByOrderId(@Param("orderId") Integer orderId);
}

OrderItemMapper.xml

 <resultMap id="OrderItemVoMap" type="com.cgl.ssm.model.vo.OrderItemVo">
    <result property="orderItemId" column="order_item_id"></result>
    <result property="productId" column="product_id"></result>
    <result property="quantity" column="quantity"></result>
    <result property="oid" column="oid"></result>
    <!--<result property="orderItems"></result>-->
    <association property="order" javaType="com.cgl.ssm.model.Order">
      <result property="orderId" column="order_id"></result>
      <result property="orderNo" column="order_no"></result>
    </association>
  </resultMap>
  
<select id="selectByOrderItemId" resultMap="OrderItemVoMap" parameterType="java.lang.Integer" >
    select * from t_hibernate_order o,t_hibernate_order_item oi where o.order_id=oi.oid
  and oi.order_item_id = #{orderItemId}
  </select>

OrderItemMapper.java

package com.cgl.ssm.mapper;

import com.cgl.ssm.model.OrderItem;
import com.cgl.ssm.model.vo.OrderItemVo;
import org.apache.ibatis.annotations.Param;
import org.springframework.stereotype.Repository;

import java.util.List;

@Repository

public interface OrderItemMapper {
    int deleteByPrimaryKey(Integer orderItemId);

    int insert(OrderItem record);

    int insertSelective(OrderItem record);

    OrderItem selectByPrimaryKey(Integer orderItemId);

    int updateByPrimaryKeySelective(OrderItem record);

    int updateByPrimaryKey(OrderItem record);

    List<OrderItemVo> selectByOrderItemId(@Param("orderItemId") Integer orderItemId);
}

OneToManyService

package com.cgl.ssm.service;

import com.cgl.ssm.model.vo.OrderItemVo;
import com.cgl.ssm.model.vo.OrderVo;

import java.util.List;

/**
 * @author caoguangli
 * @site www.xiaomage.com
 * @company
 * @create  2019-10-23 19:26
 */
public interface OneToManyService {
    List<OrderVo> selectByOrderId(Integer orderId);
    List<OrderItemVo> selectByOrderItemId(Integer orderItemId);

}

OneToManyServiceImpl

package com.cgl.ssm.service.impl;

import com.cgl.ssm.mapper.OrderItemMapper;
import com.cgl.ssm.mapper.OrderMapper;
import com.cgl.ssm.model.vo.OrderItemVo;
import com.cgl.ssm.model.vo.OrderVo;
import com.cgl.ssm.service.OneToManyService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.util.List;

/**
 * @author caoguangli
 * @site www.xiaomage.com
 * @company
 * @create  2019-10-23 19:26
 */

@Service
public class OneToManyServiceImpl implements OneToManyService {
    @Autowired
    private OrderMapper orderMapper;
    @Autowired
    private OrderItemMapper orderItemMapper;
    @Override
    public List<OrderVo> selectByOrderId(Integer orderId) {
        return orderMapper.selectByOrderId(orderId);
    }

    @Override
    public List<OrderItemVo> selectByOrderItemId(Integer orderItemId) {
        return orderItemMapper.selectByOrderItemId(orderItemId);
    }
}

One2ManyServiceImplTest

package com.cgl.ssm.service.impl;

import com.cgl.ssm.model.OrderItem;
import com.cgl.ssm.model.vo.OrderItemVo;
import com.cgl.ssm.model.vo.OrderVo;
import com.cgl.ssm.service.OneToManyService;
import com.cgl.ssm.test.SpringJunitBaseTest;
import org.junit.After;
import org.junit.Before;
import org.junit.Test;
import org.springframework.beans.factory.annotation.Autowired;

import java.util.List;

/**
 * @author caoguangli
 * @site www.xiaomage.com
 * @company
 * @create  2019-10-23 19:33
 */
public class OneToManyServiceImplTest extends SpringJunitBaseTest {

    @Autowired
    private OneToManyService oneToManyService;
    @Before
    public void setUp() throws Exception {
    }

    @After
    public void tearDown() throws Exception {
    }

    @Test
    public void selectByOrderId() {
        List<OrderVo> orderVos = oneToManyService.selectByOrderId(8);
        OrderVo orderVo = orderVos.get(0);
        System.out.println(orderVo);
        for (OrderItem orderItem : orderVo.getOrderItems()) {
            System.out.println(orderItem);
        }
    }

    @Test
    public void selectByOrderItemId() {
        List<OrderItemVo> orderItemVos = oneToManyService.selectByOrderItemId(36);
        OrderItemVo orderItemVo = orderItemVos.get(0);
        System.out.println(orderItemVo);
        System.out.println(orderItemVo.getOrder());
    }
}

运行结果：

多对多

首先先用逆向生成工具生成t_hibernate_book、t_hibernate_book_category、t_hibernate_category，这两张表对应的model与mapper

实体类

HbookVo

package com.cgl.ssm.model.vo;

import com.cgl.ssm.model.Category;
import com.cgl.ssm.model.Hbook;

import java.util.ArrayList;
import java.util.List;

/**
 * @author caoguangli
 * @site www.xiaomage.com
 * @company
 * @create  2019-10-23 19:42
 */
public class HbookVo extends Hbook {
    private List<Category> categories = new ArrayList<>();

    public List<Category> getCategories() {
        return categories;
    }

    public void setCategories(List<Category> categories) {
        this.categories = categories;
    }
}

CategoryVo

package com.cgl.ssm.model.vo;

import com.cgl.ssm.model.Category;
import com.cgl.ssm.model.Hbook;

import java.util.ArrayList;
import java.util.List;

/**
 * @author caoguangli
 * @site www.xiaomage.com
 * @company
 * @create  2019-10-23 19:44
 */
public class CategoryVo extends Category {
    private List<Hbook> hbooks = new ArrayList<>();

    public List<Hbook> getHbooks() {
        return hbooks;
    }

    public void setHbooks(List<Hbook> hbooks) {
        this.hbooks = hbooks;
    }
}

HbookMapper.xml

<resultMap id="HbookVoMap" type="com.cgl.ssm.model.vo.HbookVo">
    <result property="bookId" column="book_id"></result>
    <result property="bookName" column="book_name"></result>
    <result property="price" column="price"></result>
    <!--<result property="orderItems"></result>-->
    <collection property="categories" ofType="com.cgl.ssm.model.Category">
      <result property="categoryId" column="category_id"></result>
      <result property="categoryName" column="category_name"></result>
    </collection>
  </resultMap>
  
 <select id="selectByBid" resultMap="HbookVoMap" parameterType="java.lang.Integer" >
   select * from t_hibernate_book b,t_hibernate_book_category bc,t_hibernate_category c
where b.book_id = bc.bid and bc.cid = c.category_id
and b.book_id = #{bid}
  </select>

HbookMapper.java

package com.cgl.ssm.mapper;

import com.cgl.ssm.model.Hbook;
import com.cgl.ssm.model.vo.HbookVo;
import org.apache.ibatis.annotations.Param;
import org.springframework.stereotype.Repository;

@Repository
public interface HbookMapper {
    int deleteByPrimaryKey(Integer bookId);

    int insert(Hbook record);

    int insertSelective(Hbook record);

    Hbook selectByPrimaryKey(Integer bookId);

    int updateByPrimaryKeySelective(Hbook record);

    int updateByPrimaryKey(Hbook record);

    HbookVo selectByBid(@Param("bid") Integer bid);
}

CategoryVoMapper.xml

 <resultMap id="CategoryVoMap" type="com.cgl.ssm.model.vo.CategoryVo">
    <result property="categoryId" column="category_id"></result>
    <result property="categoryName" column="category_name"></result>
    <!--<result property="orderItems"></result>-->
    <collection property="hbooks" ofType="com.cgl.ssm.model.Hbook">
      <result property="bookId" column="book_id"></result>
      <result property="bookName" column="book_name"></result>
      <result property="price" column="price"></result>
    </collection>
  </resultMap>

 <select id="selectByCid" resultMap="CategoryVoMap" parameterType="java.lang.Integer" >
   select * from t_hibernate_book b,t_hibernate_book_category bc,t_hibernate_category c
where b.book_id = bc.bid and bc.cid = c.category_id
and c.category_id = #{cid}
  </select>

CategoryVoMapper.java

package com.cgl.ssm.mapper;

import com.cgl.ssm.model.Category;
import com.cgl.ssm.model.vo.CategoryVo;
import org.apache.ibatis.annotations.Param;
import org.springframework.stereotype.Repository;

@Repository
public interface CategoryMapper {
    int deleteByPrimaryKey(Integer categoryId);

    int insert(Category record);

    int insertSelective(Category record);

    Category selectByPrimaryKey(Integer categoryId);

    int updateByPrimaryKeySelective(Category record);

    int updateByPrimaryKey(Category record);

    CategoryVo selectByCid(@Param("cid") Integer cid);
}

ManyToManyService.java

package com.cgl.ssm.service;

import com.cgl.ssm.model.vo.CategoryVo;
import com.cgl.ssm.model.vo.HbookVo;

/**
 * @author caoguangli
 * @site www.xiaomage.com
 * @company
 * @create  2019-10-23 20:15
 */
public interface ManyToManyService {

    HbookVo selectByBid(Integer bid);
    CategoryVo selectByCid(Integer cid);
}

ManyToManyServiceImpl

package com.cgl.ssm.service.impl;

import com.cgl.ssm.mapper.CategoryMapper;
import com.cgl.ssm.mapper.HbookMapper;
import com.cgl.ssm.model.vo.CategoryVo;
import com.cgl.ssm.model.vo.HbookVo;
import com.cgl.ssm.service.ManyToManyService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

/**
 * @author caoguangli
 * @site www.xiaomage.com
 * @company
 * @create  2019-10-23 20:16
 */

@Service
public class ManyToManyServiceImpl implements ManyToManyService {

    @Autowired
    private HbookMapper hbookMapper;

    @Autowired
    private CategoryMapper categoryMapper;
    @Override
    public HbookVo selectByBid(Integer bid) {
        return hbookMapper.selectByBid(bid);
    }

    @Override
    public CategoryVo selectByCid(Integer cid) {
        return categoryMapper.selectByCid(cid);
    }
}

ManyToManyServiceImplTest

package com.cgl.ssm.service.impl;

import com.cgl.ssm.model.Category;
import com.cgl.ssm.model.Hbook;
import com.cgl.ssm.model.vo.CategoryVo;
import com.cgl.ssm.model.vo.HbookVo;
import com.cgl.ssm.service.ManyToManyService;
import com.cgl.ssm.test.SpringJunitBaseTest;
import org.junit.After;
import org.junit.Before;
import org.junit.Test;
import org.springframework.beans.factory.annotation.Autowired;

import static org.junit.Assert.*;

/**
 * @author caoguangli
 * @site www.xiaomage.com
 * @company
 * @create  2019-10-23 20:18
 */
public class ManyToManyServiceImplTest extends SpringJunitBaseTest {

    @Autowired private ManyToManyService manyToManyService;
    @Before
    public void setUp() throws Exception {
    }

    @After
    public void tearDown() throws Exception {
    }

    @Test
    public void selectByBid() {
        HbookVo hbookVo = manyToManyService.selectByBid(8);
        System.out.println(hbookVo);
        for (Category category : hbookVo.getCategories()) {
            System.out.println(category);
        }
    }

    @Test
    public void selectByCid() {
        CategoryVo categoryVo = this.manyToManyService.selectByCid(8);
        System.out.println(categoryVo);
        for (Hbook hbook : categoryVo.getHbooks()) {
            System.out.println(hbook);
        }

    }
}

运行结果：