How to SUM and SUBTRACT using SQL?

问题

I am using MySQL and I have two tables:

master_table

ORDERNO
ITEM
QTY

stock_bal

ITEM
BAL_QTY

Master table has duplicate ORDERNO and ITEM values. I have get total QTY using SQL 'GROUP BY' clause.

I need to deduct/subtract BAL_QTY from SUM of ITEM (master_table). I've got SUM QTY value using query (actually there are many rows).

回答1:

I think this is what you're looking for. NEW_BAL is the sum of QTYs subtracted from the balance:

SELECT   master_table.ORDERNO,
         master_table.ITEM,
         SUM(master_table.QTY),
         stock_bal.BAL_QTY,
         (stock_bal.BAL_QTY - SUM(master_table.QTY)) AS NEW_BAL
FROM     master_table INNER JOIN
         stock_bal ON master_bal.ITEM = stock_bal.ITEM
GROUP BY master_table.ORDERNO,
         master_table.ITEM

If you want to update the item balance with the new balance, use the following:

UPDATE stock_bal
SET    BAL_QTY = BAL_QTY - (SELECT   SUM(QTY)
                            FROM     master_table
                            GROUP BY master_table.ORDERNO,
                                     master_table.ITEM)

This assumes you posted the subtraction backward; it subtracts the quantities in the order from the balance, which makes the most sense without knowing more about your tables. Just swap those two to change it if I was wrong:

(SUM(master_table.QTY) - stock_bal.BAL_QTY) AS NEW_BAL

回答2:

I'm not sure exactly what you want, but I think it's along the lines of:

SELECT `Item`, `qty`-`BAL_QTY` as `qty` FROM ((SELECT Item, SUM(`QTY`) as qty FROM `master_table` GROUP BY `ITEM`) as A NATURAL JOIN `stock_table`) as B

回答3:

ah homework...

So wait, you need to deduct the balance of items in stock from the total number of those items that have been ordered? I have to tell you that sounds a bit backwards. Generally I think people do it the other way round. Deduct the total number of items ordered from the balance.

If you really need to do that though... Assuming that ITEM is unique in stock_bal...

SELECT s.ITEM, SUM(m.QTY) - s.QTY AS result
FROM stock_bal s
INNER JOIN master_table m ON m.ITEM = s.ITEM
GROUP BY s.ITEM, s.QTY

回答4:

I have tried this kind of technique. Multiply the subtract from data by (-1) and then sum() the both amount then you will get subtracted amount.

-- Loan Outstanding
    select  'Loan Outstanding' as Particular, sum(Unit), sum(UptoLastYear), sum(ThisYear), sum(UptoThisYear)
    from
    (
        select 
            sum(laod.dr) as Unit,
            sum(if(lao.created_at <= '2014-01-01',laod.dr,0)) as UptoLastYear,
            sum(if(lao.created_at between '2014-01-01' and '2015-07-14',laod.dr,0)) as ThisYear,
            sum(if(lao.created_at <= '2015-07-14',laod.dr,0)) as UptoThisYear
        from loan_account_opening as lao
        inner join loan_account_opening_detail as laod on lao.id=laod.loan_account_opening_id
        where lao.organization = 3
        union
        select
            sum(lr.installment)*-1 as Unit,
            sum(if(lr.created_at <= '2014-01-01',lr.installment,0))*-1 as UptoLastYear,
            sum(if(lr.created_at between '2014-01-01' and '2015-07-14',lr.installment,0))*-1 as ThisYear,
            sum(if(lr.created_at <= '2015-07-14',lr.installment,0))*-1 as UptoThisYear
        from loan_recovery as lr
        inner join loan_account_opening as lo on lr.loan_account_opening_id=lo.id
        where lo.organization = 3
    ) as t3

回答5:

An example for subtraction is given below:

Select value1 - (select value2 from AnyTable1) from AnyTable2

value1 & value2 can be count,sum,average output etc. But the values should be comapatible

回答6:

Simple copy & paste example with subqueries, Note, that both queries should return 1 row:

select
(select sum(items_1) from items_table_1 where ...)
-
(select count(items_2) from items_table_1 where ...) 

as difference

来源：https://stackoverflow.com/questions/6715095/how-to-sum-and-subtract-using-sql

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mysql

sql

aggregate-functions