如何在mysql查询中求和的总和

Question

SELECT a.id AS supplier, sum( processed_weight ) AS total_qty
FROM supplier_inward a
INNER JOIN warehouseb ON a.id = b.supplier
WHERE a.master_product_id = '38'
GROUP BY b.supplier

输出存在

supplier    total_qty
12046      475.00
12482      99.00

输出需要

total_qty
574.00

这里我需要这个查询中的总和(total_qty)？如何实现这一目标

Answer 1

只需修改GROUP BY,添加WITH ROLLUP:

SELECT a.id AS supplier, sum( processed_weight ) AS total_qty
FROM supplier_inward a
  INNER JOIN warehouseb ON a.id = b.supplier
WHERE a.master_product_id = '38'
GROUP BY b.supplier
  WITH ROLLUP

输出:

supplier    total_qty
12046       475.00
12482        99.00
NULL        574.00

Answer 2

这个怎么样：

SELECT SUM(iQuery.total_qty) as iTotal
FROM
    (SELECT a.id AS supplier, sum( processed_weight ) AS total_qty
    FROM supplier_inward a
    INNER JOIN warehouseb ON a.id = b.supplier
    WHERE a.master_product_id = '38'
    GROUP BY b.supplier) as iQuery