请大佬帮忙看看这段sql还能怎么优化一下

Question

请大佬帮忙看看这段sql还能怎么优化一下，目前看group by还是有问题，执行计划看group by还是有问题的。。。

select 
c.code as deptCode,
a.item_id as itemId,
a.item_code as itemCode,
sum(a.adjust_num) as adjustNum,
0 as status,
group_concat(a.id separator '-') as detailIds, 
c.detail_reason as reasonCode
    from 表 a,表 c
    where c.ware_id = #{wareId}
    and a.ware_id = #{wareId}
    and c.id = a.adjust_id
    and a.gmt_modified between #{Start} and #{End}
    and a.status = 2
    and c.describe = #{describe}
    and (c.source_mode is null or c.source_mode = 14)
    <if test="itemCode != null">
      and a.item_code = #{itemCode}
    </if>
    <if test="deptCode != null">
      and c.dept_code = #{deptCode}
    </if>
    <if test="deptCodes != null and deptCodes.size > 0">
      and c.dept_code in
      <foreach item="iDeptCode" collection="deptCodes" open="(" separator="," close=")">
        #{iDeptCode}
      </foreach>
    </if>
    <if test="excludeDetailIds != null and excludeDetailIds.size > 0">
      and a.id not in
      <foreach item="iExcludeDetailId" collection="excludeDetailIds" open="(" separator="," close=")">
        #{iExcludeDetailId}
      </foreach>
    </if>
    <if test="reasonCode != null">
      and c.detail_reason = #{reasonCode}
    </if>
    group by c.dept_code,a.item_code

执行计划：第一行是表c，第二行是表a

Answer 1

https://ask.csdn.net/questions/1064988 一样的问题