自定义Mappter

自定义Mappter

package com.imooc.service;

import com.imooc.pojo.Category;
import com.imooc.pojo.vo.CategoryVO;
import com.imooc.pojo.vo.NewItemsVO;

import java.util.List;

public interface CategoryService {

    /**
     * 查询所有一级分类
     * @return
     */
    public List<Category> queryAllRootLevelCat();

    /**
     * 根据一级分类id查询子分类信息
     * @param rootCatId
     * @return
     */
    public List<CategoryVO> getSubCatList(Integer rootCatId);

    /**
     * 查询首页每个一级分类下的6条最新商品数据
     * @param rootCatId
     * @return
     */
    public List<NewItemsVO> getSixNewItemsLazy(Integer rootCatId);

}

package com.imooc.service.impl;

import com.imooc.mapper.CarouselMapper;
import com.imooc.mapper.CategoryMapper;
import com.imooc.mapper.CategoryMapperCustom;
import com.imooc.pojo.Carousel;
import com.imooc.pojo.Category;
import com.imooc.pojo.vo.CategoryVO;
import com.imooc.pojo.vo.NewItemsVO;
import com.imooc.service.CarouselService;
import com.imooc.service.CategoryService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Propagation;
import org.springframework.transaction.annotation.Transactional;
import tk.mybatis.mapper.entity.Example;

import java.util.HashMap;
import java.util.List;
import java.util.Map;

@Service
public class CategoryServiceImpl implements CategoryService {

    @Autowired
    private CategoryMapper categoryMapper;

    @Autowired
    private CategoryMapperCustom categoryMapperCustom;

    @Transactional(propagation = Propagation.SUPPORTS)
    @Override
    public List<Category> queryAllRootLevelCat() {

        Example example = new Example(Category.class);
        Example.Criteria criteria = example.createCriteria();
        criteria.andEqualTo("type", 1);

        List<Category> result =  categoryMapper.selectByExample(example);

        return result;
    }

    @Transactional(propagation = Propagation.SUPPORTS)
    @Override
    public List<CategoryVO> getSubCatList(Integer rootCatId) {
        return categoryMapperCustom.getSubCatList(rootCatId);
    }

    @Transactional(propagation = Propagation.SUPPORTS)
    @Override
    public List<NewItemsVO> getSixNewItemsLazy(Integer rootCatId) {

        Map<String, Object> map = new HashMap<>();
        map.put("rootCatId", rootCatId);

        return categoryMapperCustom.getSixNewItemsLazy(map);
    }
}

package com.imooc.mapper;

import com.imooc.pojo.vo.CategoryVO;
import com.imooc.pojo.vo.NewItemsVO;
import org.apache.ibatis.annotations.Param;

import java.util.List;
import java.util.Map;

public interface CategoryMapperCustom {

    public List<CategoryVO> getSubCatList(Integer rootCatId);

    public List<NewItemsVO> getSixNewItemsLazy(@Param("paramsMap") Map<String, Object> map);
}

<?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.imooc.mapper.CategoryMapperCustom" >

  <resultMap id="myCategoryVO" type="com.imooc.pojo.vo.CategoryVO">
    <id column="id" property="id"/>
    <result column="name" property="name"/>
    <result column="type" property="type"/>
    <result column="fatherId" property="fatherId"/>

    <!--
      collection 标签：用于定义关联的list集合类型的封装规则
      property：对应三级分类的list属性名
      ofType：集合的类型，三级分类的vo
    -->
    <collection property="subCatList" ofType="com.imooc.pojo.vo.SubCategoryVO">
      <id column="subId" property="subId"/>
      <result column="subName" property="subName"/>
      <result column="subType" property="subType"/>
      <result column="subFatherId" property="subFatherId"/>
    </collection>
  </resultMap>

  <select id="getSubCatList" resultMap="myCategoryVO" parameterType="int">
    SELECT
        f.id as id,
        f.`name` as `name`,
        f.type as type,
        f.father_id as fatherId,
        c.id as subId,
        c.`name` as subName,
        c.type as subType,
        c.father_id as subFatherId
    FROM
        category f
    LEFT JOIN
        category c
    on
        f.id = c.father_id
    WHERE
        f.father_id = #{rootCatId}
  </select>

    <resultMap id="myNewItemsVO" type="com.imooc.pojo.vo.NewItemsVO">
        <id column="rootCatId" property="rootCatId"/>
        <result column="rootCatName" property="rootCatName"/>
        <result column="slogan" property="slogan"/>
        <result column="catImage" property="catImage"/>
        <result column="bgColor" property="bgColor"/>

        <collection property="simpleItemList" ofType="com.imooc.pojo.vo.SimpleItemVO">
            <id column="itemId" property="itemId"/>
            <result column="itemName" property="itemName"/>
            <result column="itemUrl" property="itemUrl"/>
        </collection>
    </resultMap>

    <select id="getSixNewItemsLazy" resultMap="myNewItemsVO" parameterType="Map">
        SELECT
            f.id as rootCatId,
            f.`name` as rootCatName,
            f.slogan as slogan,
            f.cat_image as catImage,
            f.bg_color as bgColor,
            i.id as itemId,
            i.item_name as itemName,
            ii.url as itemUrl,
            i.created_time as createdTime
        FROM
            category f
        LEFT JOIN items i ON f.id = i.root_cat_id
        LEFT JOIN items_img ii ON i.id = ii.item_id
        WHERE
            f.type = 1
        AND
            i.root_cat_id = #{paramsMap.rootCatId}
        AND
            ii.is_main = 1
        ORDER BY
            i.created_time
        DESC
        LIMIT 0,6
    </select>


</mapper>