将两个不同的表相加，然后减去其总数

Question

i have this problem with me on how to sum total value from two different table and then after getting its total i want to subtract it. for example i have table "rsales" and "sales" and i have these ff vlue below.

data from "rsales"

id | total | pcode |
1  | 100   | 2143  |
2  | 100   | 2143  |
3  | 50    | 2222  |
4  | 50    | 2222  |

data from "sales"

id | total | pcode |
7  | 100   | 2143  |
8  | 50    | 2222  |

my problem is this. i want to sum all "total" values from sales and sum "total"value from rsales group by pcode.and then after getting its sum i want to subtract it. my page must be something like this.

   total    pcode
 | 100    | 2143  |
 | 50     | 2222  |

i have this ff code but it doesnt wor for me

sql "select sum(rsales.total)- sum(sales.total) as t1 where pcode = rsales.pcode"

Answer 1

Use:

SELECT 
    SUM(r.total)-(
                   SELECT SUM(s.total) 
                   FROM sales AS s WHERE r.pcode=s.pcode
                  ) as total, 
    r.pcode 

    FROM rsales AS r 

    GROUP BY r.pcode;

Output:

+--+--+--+--+--+-
| total | pcode |
+--+--+--+--+--+-
| 100   | 2143  |
| 50    | 2222  |
+--+--+--+--+--+-
2 rows in set

Answer 2

Have you tried something like this?

SELECT
    SUM(L.total) as lTotal, SUM(R.total) as rTotal
FROM
    sales L
INNER JOIN rsales R 
    ON
        R.pcode = L.pcode
GROUP BY L.pcode

If you get expected values from both tables you can easily add Additions and Subtruction in FROM clause.

Answer 3

There's no joins needed to do this. This solution works if some pcodes are only in one table:

select SUM(total), pcode from (
        select sum(total) as total, pcode from rsales group by pcode
    union all
        select SUM(-total) as total, pcode from sales group by pcode) salesTables
 group by pcode