如何在MySQL中组合并从三个不同的相关表中获取总和？

有三个相关表格： 操作（id、名称） 价格表（id、操作id（链接到操作表）、成本） 会计（id、价目表\u id（链接到价目表）、数量）

如何得到一张桌子，比如

NAME            SUMMARY_COST            SUMMARY_QUANTITY
milling         result of 2*750                2
threading       result of 1*444                1
...                     ...                   ...
overall         2*750+1*444+...             2+1+...

我尝试一开始就分组两张表：

select operations.name, sum(pricelists.cost) total
from operations
left join pricelists on pricelists.operations_id*accounting_quantity = operations.id*accounting.quantity
group by operations.id

但它还没有起作用

一个小数据库：

CREATE TABLE operations (id INT PRIMARY KEY AUTO_INCREMENT,
                         name VARCHAR (100));
CREATE TABLE pricelists (id INT PRIMARY KEY,  operations_id INT NOT NULL, cost DECIMAL(10,2),
                  FOREIGN KEY (operations_id) REFERENCES  operations (id));
CREATE TABLE accounting  (id INT PRIMARY KEY, pricelists_id INT NOT NULL, quantity INT,
                        FOREIGN KEY (pricelists_id) REFERENCES  pricelists (id));


INSERT INTO operations (name) VALUES
    ('milling'),
    ('threading'),
    ('grinding'),
    ('welding'),
    ('brazing'),
    ('soldering'),
    ('riveting');

INSERT INTO pricelists (id, operations_id, cost) VALUES
    (1, 2, 750),
    (2, 1, 444),
    (3, 3, 123),
    (4, 4, 450),
    (5, 5, 375),
    (6, 6, 250),
    (7, 7, 232);

INSERT INTO accounting (id, pricelists_id, quantity) VALUES
    (1, 7, 2),
    (2, 2, 5),
    (3, 4, 2),
    (4, 1, 1),
    (5, 3, 4);

康斯特尔：

select o.name, sum(a.quantity * pl.cost) total, sum(a.quantity) quantity
from operations o
left join pricelists pl on pl.operations_id = o.id
left join accounting a  on a.pricelists_id = pl.id
group by o.name

---

您只需在查询的最后添加带有rollup的

，即可生成摘要行。
谢谢！它起作用了。可以添加最后一行“总体”，这表示列的总和吗？@antonio_fergusson：答案中已经提到了这一点。只需在查询的最后添加带有rollup的
。