MyBatis关联关系

Posted 2021-03-25 小蜜疯

一、一对多关联关系

1.通过generatorConfig.xml中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

<table schema="" tableName="t_hibernate_Book" domainObjectName="HBook"
               enableCountByExample="false" enableDeleteByExample="false"
               enableSelectByExample="false" enableUpdateByExample="false">
        </table>
        <table schema="" tableName="t_hibernate_order" domainObjectName="Order"
               enableCountByExample="false" enableDeleteByExample="false"
               enableSelectByExample="false" enableUpdateByExample="false">
        </table>
        <table schema="" tableName="t_hibernate_order_item" domainObjectName="OrderItem"
               enableCountByExample="false" enableDeleteByExample="false"
               enableSelectByExample="false" enableUpdateByExample="false">
        </table>
        <table schema="" tableName="t_hibernate_category" domainObjectName="Category"
               enableCountByExample="false" enableDeleteByExample="false"
               enableSelectByExample="false" enableUpdateByExample="false">
        </table>
        <table schema="" tableName="t_hibernate_book_category" domainObjectName="BookCategory"
               enableCountByExample="false" enableDeleteByExample="false"
               enableSelectByExample="false" enableUpdateByExample="false">
        </table>

 

Order.java(订单实体)

package com.hmc.ssm.model;

public class Order {
    private Integer orderId;

    private String orderNo;

    public Order(Integer orderId, String orderNo) {
        this.orderId = orderId;
        this.orderNo = orderNo;
    }

    public Order() {
        super();
    }

    public Integer getOrderId() {
        return orderId;
    }

    public void setOrderId(Integer orderId) {
        this.orderId = orderId;
    }

    public String getOrderNo() {
        return orderNo;
    }

    public void setOrderNo(String orderNo) {
        this.orderNo = orderNo;
    }

    @Override
    public String toString() {
        return "Order{" +
                "orderId=" + orderId +
                ", orderNo=\'" + orderNo + \'\\\'\' +
                \'}\';
    }
}

OrderMapper

@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);

}

 

 

OrderMapper.xml

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd" >
<mapper namespace="com.ningjie.ssm.mapper.OrderMapper" >
  <resultMap id="BaseResultMap" type="com.hmc.ssm.model.Order" >
    <constructor >
      <idArg column="order_id" jdbcType="INTEGER" javaType="java.lang.Integer" />
      <arg column="order_no" jdbcType="VARCHAR" javaType="java.lang.String" />
    </constructor>
  </resultMap>
  <resultMap id="orderVoMap" type="com.hmc.ssm.model.vo.OrderVo">
    <result property="orderId" column="order_id"></result>
    <result property="orderNo" column="order_no"></result>
    <collection property="orderItems" ofType="com.hmc.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>
  <sql id="Base_Column_List" >
    order_id, order_no
  </sql>
  <select id="selectByPrimaryKey" resultMap="BaseResultMap" parameterType="java.lang.Integer" >
    select 
    <include refid="Base_Column_List" />
    from t_hibernate_order
    where order_id = #{orderId,jdbcType=INTEGER}
  </select>
  <delete id="deleteByPrimaryKey" parameterType="java.lang.Integer" >
    delete from t_hibernate_order
    where order_id = #{orderId,jdbcType=INTEGER}
  </delete>
  <insert id="insert" parameterType="com.hmc.ssm.model.Order" >
    insert into t_hibernate_order (order_id, order_no)
    values (#{orderId,jdbcType=INTEGER}, #{orderNo,jdbcType=VARCHAR})
  </insert>
  <insert id="insertSelective" parameterType="com.hmc.ssm.model.Order" >
    insert into t_hibernate_order
    <trim prefix="(" suffix=")" suffixOverrides="," >
      <if test="orderId != null" >
        order_id,
      </if>
      <if test="orderNo != null" >
        order_no,
      </if>
    </trim>
    <trim prefix="values (" suffix=")" suffixOverrides="," >
      <if test="orderId != null" >
        #{orderId,jdbcType=INTEGER},
      </if>
      <if test="orderNo != null" >
        #{orderNo,jdbcType=VARCHAR},
      </if>
    </trim>
  </insert>
  <update id="updateByPrimaryKeySelective" parameterType="com.hmc.ssm.model.Order" >
    update t_hibernate_order
    <set >
      <if test="orderNo != null" >
        order_no = #{orderNo,jdbcType=VARCHAR},
      </if>
    </set>
    where order_id = #{orderId,jdbcType=INTEGER}
  </update>
  <update id="updateByPrimaryKey" parameterType="com.hmc.ssm.model.Order" >
    update t_hibernate_order
    set order_no = #{orderNo,jdbcType=VARCHAR}
    where order_id = #{orderId,jdbcType=INTEGER}
  </update>
  <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>
</mapper>

 

 

用下面的OrderVo类继承订单

用一个list集合来放置多方(

OrderItem

)

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;
    }
}

 

 

OrderItem 

public class OrderItem {
    private Integer orderItemId;

    private Integer productId;

    private Integer quantity;

    private Integer oid;

    public OrderItem(Integer orderItemId, Integer productId, Integer quantity, Integer oid) {
        this.orderItemId = orderItemId;
        this.productId = productId;
        this.quantity = quantity;
        this.oid = oid;
    }

    public OrderItem() {
        super();
    }

    public Integer getOrderItemId() {
        return orderItemId;
    }

    public void setOrderItemId(Integer orderItemId) {
        this.orderItemId = orderItemId;
    }

    public Integer getProductId() {
        return productId;
    }

    public void setProductId(Integer productId) {
        this.productId = productId;
    }

    public Integer getQuantity() {
        return quantity;
    }

    public void setQuantity(Integer quantity) {
        this.quantity = quantity;
    }

    public Integer getOid() {
        return oid;
    }

    public void setOid(Integer oid) {
        this.oid = oid;
    }

    @Override
    public String toString() {
        return "OrderItem{" +
                "orderItemId=" + orderItemId +
                ", productId=" + productId +
                ", quantity=" + quantity +
                ", oid=" + oid +
                \'}\';
    }
}

 

OrderItemVo.java

public class OrderItemVo extends OrderItem {
private Order order;

    public Order getOrder() {
        return order;
    }

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

 

 OrderItemMapper

@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);
}

 

OrderMapper.xml

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd" >
<mapper namespace="com.hmc.ssm.mapper.OrderItemMapper" >
  <resultMap id="BaseResultMap" type="com.hmc.ssm.model.OrderItem" >
    <constructor >
      <idArg column="order_item_id" jdbcType="INTEGER" javaType="java.lang.Integer" />
      <arg column="product_id" jdbcType="INTEGER" javaType="java.lang.Integer" />
      <arg column="quantity" jdbcType="INTEGER" javaType="java.lang.Integer" />
      <arg column="oid" jdbcType="INTEGER" javaType="java.lang.Integer" />
    </constructor>
  </resultMap>

  <resultMap id="orderItemVoMap" type="com.hmc.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>
    <association property="order" javaType="com.hmc.ssm.model.Order">
      <result property="orderId" column="order_id"></result>
      <result property="orderNo" column="order_no"></result>
    </association>
  </resultMap>

  <sql id="Base_Column_List" >
    order_item_id, product_id, quantity, oid
  </sql>
  <select id="selectByPrimaryKey" resultMap="BaseResultMap" parameterType="java.lang.Integer" >
    select 
    <include refid="Base_Column_List" />
    from t_hibernate_order_item
    where order_item_id = #{orderItemId,jdbcType=INTEGER}
  </select>
  <delete id="deleteByPrimaryKey" parameterType="java.lang.Integer" >
    delete from t_hibernate_order_item
    where order_item_id = #{orderItemId,jdbcType=INTEGER}
  </delete>
  <insert id="insert" parameterType="com.hmc.ssm.model.OrderItem" >
    insert into t_hibernate_order_item (order_item_id, product_id, quantity, 
      oid)
    values (#{orderItemId,jdbcType=INTEGER}, #{productId,jdbcType=INTEGER}, #{quantity,jdbcType=INTEGER}, 
      #{oid,jdbcType=INTEGER})
  </insert>
  <insert id="insertSelective" parameterType="com.hmc.ssm.model.OrderItem" >
    insert into t_hibernate_order_item
    <trim prefix="(" suffix=")" suffixOverrides="," >
      <if test="orderItemId != null" >
        order_item_id,
      </if>
      <if test="productId != null" >
        product_id,
      </if>
      <if test="quantity != null" >
        quantity,
      </if>
      <if test="oid != null" >
        oid,
      </if>
    </trim>
    <trim prefix="values (" suffix=")" suffixOverrides="," >
      <if test="orderItemId != null" >
        #{orderItemId,jdbcType=INTEGER},
      </if>
      <if test="productId != null" >
        #{productId,jdbcType=INTEGER},
      </if>
      <if test="quantity != null" >
        #{quantity,jdbcType=INTEGER},
      </if>
      <if test="oid != null" >
        #{oid,jdbcType=INTEGER},
      </if>
    </trim>
  </insert>
  <update id="updateByPrimaryKeySelective" parameterType="com.hmc.ssm.model.OrderItem" >
    update t_hibernate_order_item
    <set >
      <if test="productId != null" >
        product_id = #{productId,jdbcType=INTEGER},
      </if>
      <if test="quantity != null" >
        quantity = #{quantity,jdbcType=INTEGER},
      </if>
      <if test="oid != null" >
        oid = #{oid,jdbcType=INTEGER},
      </if>
    </set>
    where order_item_id = #{orderItemId,jdbcType=INTEGER}
  </update>
  <update id="updateByPrimaryKey" parameterType="com.hmc.ssm.model.OrderItem" >
    update t_hibernate_order_item
    set product_id = #{productId,jdbcType=INTEGER},
      quantity = #{quantity,jdbcType=INTEGER},
      oid = #{oid,jdbcType=INTEGER}
    where order_item_id = #{orderItemId,jdbcType=INTEGER}
  </update>

  <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>
</mapper>

 

 

OneToManyService

public interface OneToManyService {
    List<OrderItemVo> selectByOrderItemId(Integer orderItemId);
    List<OrderVo> selectByOrderId(Integer orderId);
}

 

 

OneToManyServiceImpl

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

    @Override
    public List<OrderVo> selectByOrderId(Integer orderId) {
        return orderMapper.selectByOrderId(orderId);
    }
}

 

 

 

OneToManyServiceImplTest

public class OneToManyServiceImplTest extends SpringBaseTest {
@Autowired
private OneToManyService oneToManyService;
    @Test
    public void selectByOrderItemId() {
        List<OrderItemVo> orderItemVos = oneToManyService.selectByOrderItemId(36);
        OrderItemVo orderItemVo = orderItemVos.get(0);
        System.out.println(orderItemVo);
        System.out.println(orderItemVo.getOrder());

    }

    @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);
        }
    }
}

 

 

 

 

 

 

 

 

 

 

 

二.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

Hbook

public class HBook {
    private Integer bookId;

    private String bookName;

    private Float price;

    public HBook(Integer bookId, String bookName, Float price) {
        this.bookId = bookId;
        this.bookName = bookName;
        this.price = price;
    }

    public HBook() {
        super();
    }

    public Integer getBookId() {
        return bookId;
    }

    public void setBookId(Integer bookId) {
        this.bookId = bookId;
    }

    public String getBookName() {
        return bookName;
    }

    public void setBookName(String bookName) {
        this.bookName = bookName;
    }

    public Float getPrice() {
        return price;
    }

    public void setPrice(Float price) {
        this.price = price;
    }

    @Override
    public String toString() {
        return "HBook{" +
                "bookId=" + bookId +
                ", bookName=\'" + bookName + \'\\\'\' +
                ", price=" + price +
                \'}\';
    }
}

 

HbookVo

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;
    }
}

HbookMapper

@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);
}

HbookMapper.xml

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd" >
<mapper namespace="com.ningjie.ssm.mapper.HBookMapper" >
  <resultMap id="BaseResultMap" type="com.hmc.ssm.model.HBook" >
    <constructor >
      <idArg column="book_id" jdbcType="INTEGER" javaType="java.lang.Integer" />
      <arg column="book_name" jdbcType="VARCHAR" javaType="java.lang.String" />
      <arg column="price" jdbcType="REAL" javaType="java.lang.Float" />
    </constructor>
  </resultMap>

  <resultMap id="HbookVoMap" type="com.hmc.ssm.model.vo.HbookVo">
    <result property="bookId" column="book_id"></result>
    <result property="bookName" column="book_name"></result>
    <result property="price" column="price"></result>
    <collection property="categories" ofType="com.hmc.ssm.model.Category">
      <result property="categoryId" column="category_id"></result>
      <result property="categoryName" column="category_Name"></result>
    </collection>
  </resultMap>
  <sql id="Base_Column_List" >
    book_id, book_name, price
  </sql>
  <select id="selectByPrimaryKey" resultMap="BaseResultMap" parameterType="java.lang.Integer" >
    select 
    <include refid="Base_Column_List" />
    from t_hibernate_book
    where book_id = #{bookId,jdbcType=INTEGER}
  </select>
  <delete id="deleteByPrimaryKey" parameterType="java.lang.Integer" >
    delete from t_hibernate_book
    where book_id = #{bookId,jdbcType=INTEGER}
  SpringBoot与Mybatis整合（包含generate自动生成代码工具，数据库表一对一，一对多，关联关系中间表的查询）

 MyBatis_关联关系查询
 mybatis一对一关联关系映射
 Mybatis之关联关系（一对多多对多）
 mybatis xml数据层框架应用--Mybatis关系映射之一对多关系映射
 mybatis xml数据层框架应用--Mybatis关系映射之一对一关系映射