子查询返回值不止一个如何处理

Question

根据商铺shopId查询用户tb_users得到多个用户的u_id来查询其它结果
<select id="selectStudentsStatisticalVoList" parameterType="integer" >/*parameterType="com.ruoyi.goods.entity.vo.StudentsStatisticalVo"*/
    select tus.user_name,
           tus.user_avatar,
           td.name,
            (select count(*) from tb_study_goods where tus.shop_id = sg.shop_id and tus.u_id = sg.u_id) as studyFor,
            /*count(case when is_complete = 1 then 1 else null end ) as finishNum,*/
            (select count(*) from tb_study_goods where tus.shop_id = sg.shop_id and tus.u_id = sg.u_id and sg.is_complete = 1) as finishNum,
            (select sum (study_length) from tb_study_goods where tus.shop_id = sg.shop_id and tus.u_id = sg.u_id) as studyLength,
            (select count (*) from tb_chapter_goods_rela where tcgr.shop_id = tus.shop_id and tcgr.train_id = #{trainId}) as course,
            (select create_time from tb_study_goods where tus.shop_id = sg.shop_id and tus.u_id = sg.u_id order by create_time) as createTime

           from tb_users tus
           left join tb_study_goods sg on tus.shop_id = sg.shop_id and tus.u_id = sg.u_id
           left join tb_chapter_goods_rela tcgr on tcgr.shop_id = tus.shop_id and tcgr.train_id = #{trainId}
           left join tb_department td on td.department_id = tus.depart_id
           where
           tus.shop_id = #{shopId}

</select>

Answer 1

加limit 1吧，就只返回一条了。