子查询中的分组依据

Question

试图返回每个零件号下所有订单的总和。主要问题在于选择子查询。

SELECT i.customer_no AS CustNumber,
       i.part_no AS PartNumber, 
       SUM(f.weight) AS ForecastWeight,
       (SELECT SUM(o.ord_ord_wgt)
          FROM ortord_rec o 
         WHERE (o.ord_comp_dt < 20191126 AND o.ord_comp_dt > 20190925)
         GROUP BY o.ord_cus_part_no
       ) AS UsageWeight,
       p.cpt_prog_mat
  FROM fit_part_info i  
 INNER JOIN fit_part_forecast f ON f.part_info_id = i.id
 INNER JOIN orrcpt_rec p ON i.part_no = p.cpt_cus_part_no
 INNER JOIN ortord_rec o ON i.part_no = o.ord_cus_part_no
 WHERE accounting_period IN ('201911', '201912', '202001', '202002') AND cpt_prog_mat = "Y"
 GROUP BY i.part_no, o.ord_cus_part_no, i.customer_no, p.cpt_prog_mat
 ORDER BY i.part_no;

当我运行此命令时，出现错误：

子查询未完全返回一行。

Answer 1

大概，您打算使用相关子查询：

(SELECT SUM(o.ord_ord_wgt)
 FROM ortord_rec o 
 WHERE o.ord_comp_dt < 20191126 AND
       o.ord_comp_dt > 20190925 AND
       o.ord_cus_part_no = i.part_no
) AS UsageWeight,