mybatisplus PageHelper 一对多查询 分页问题

项目中使用PageHelper进行分页查询的时候，发现分页有问题：每页显示的数量与传入的limit的参数不一致。
细细查看之后，发现是由于查询SQL是一对多查询，才会出现这样的问题。在网上查找了一些解决方案后，最终解决了，下面是整个查找问题、解决问题的记录。

 <resultMap id="GoodsList" type="com.cc.shoppingmall.pojo.vo.goods.GoodsDetailWx">
        <id column="id" property="id"/>
        <result column="goods_image" property="goodsImage"/>
        <result column="goods_name" property="goodsName"/>
        <result column="detail" property="detail"/>
        <result column="price_min" property="priceMin"/>
        <result column="price_max" property="priceMax"/>
        <result column="type_id" property="typeId"/>
        <result column="use_stock" property="useStock"/>
        <result column="type_name" property="typeName"/>
        <collection property="specs" ofType="com.cc.shoppingmall.pojo.vo.goods.GoodsDetailWx$Spec"
            javaType="java.util.List" select="getSpec" column="id">
        </collection>
    </resultMap>
    <resultMap id="specs" type="com.cc.shoppingmall.pojo.vo.goods.GoodsDetailWx$Spec">
        <result column="specId" property="id"/>
        <result column="price" property="price"/>
        <result column="stockNum" property="stockNum"/>
        <result column="title" property="title"/>
    </resultMap>
<select id="selectPageForWechatByGoodsType" resultMap="GoodsList">
        select g.id,
               g.goods_image,
               g.goods_name,
               g.detail,
               g.price_min,
               g.price_max,
               gt.id                 type_id,
               g.use_stock,
               gt.type_name
        from goods_cash_conf conf
                 inner join goods g on conf.goods_id = g.id
                 inner join goods_type gt on conf.type_id = gt.id
        where gt.id = #{typeId}
          <if test="goodsName != null and goodsName != ''">
              and g.goods_name like concat(concat("%", #{goodsName}), "%")
          </if>
          and conf.status = 1
          and g.show_wechat = 1
          and conf.is_delete = 0
          and g.is_delete = 0
          and gt.is_delete = 0
        order by gt.ord asc, g.ord asc, g.create_time desc,g.id desc
    </select>
    <select id="getSpec" parameterType="string" resultMap="specs">
        select gs.id specId, gs.price, gs.stock stockNum, gs.specification_name title
        from goods_specification gs
        where gs.is_delete = 0 and gs.goods_id = #{id}
    </select>