業務是這樣的，一個商品有不同的規格，所有規格選擇完後會出現價格，這些規格我是放在一個表裏，父子級關系。mybatis做的時候傳過來一個商品Id.然後根據商品id去找所有的規格。

<?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.***.abc.dao.GoodsSpecCategoryMapper" >
  <resultMap id="BaseResultMap" type="com.***.abc.bean.GoodsSpecCategory" >
    <id column="id" property="id" jdbcType="BIGINT" />
    <result column="spec_name" property="specName" jdbcType="VARCHAR" />
    <result column="pid" property="pid" jdbcType="BIGINT" />
    <result column="goods_info_id" property="goodsInfoId" jdbcType="BIGINT" />
    <collection property="categoryList" ofType="GoodsSpecCategory" javaType="java.util.List" column="id" select="getById"/>
 

  </resultMap>

  <!--根據父類id查找其子類別-->
  <select id="getById" resultMap="BaseResultMap" parameterType="long">
        SELECT *
        FROM goods_spec_category
        WHERE pid = #{id}
    </select>

    <!--查找所有類別(遞歸)-->
    <select id="querySpecCategoryListById" resultMap="BaseResultMap" parameterType="long">
      SELECT 
 
*  //這裏查出來的ID會作為getById的Id去查詢子類
      FROM goods_spec_category
      WHERE goods_info_id = #{infoId} AND pid IS NULL    //infoId是傳過來的商品id

    </select>

</mapper>

商品表的xml裏的

<resultMap id="baseResultMap" type="com.***.abc.dto.GoodsInfoDto" >
    <id column="id" property="id" jdbcType="BIGINT" />
    <result column="goods_type" property="goodsType" jdbcType="VARCHAR" />
      <collection property="goodsSpecCategory" fetchType="eager" ofType="com.***.abc.bean.GoodsSpecCategory" column="id"
                  javaType
 
="ArrayList" select="com.***.abc.dao.GoodsSpecCategoryMapper.querySpecCategoryListById"/>

  </resultMap>

GoodsSpecCategoryMapper中添加接口

public interface GoodsSpecCategoryMapper {

     public List querySpecCategoryListById(@Param("infoId") Long infoId);

}

mybatis中遞歸查詢