Update column using the same column from another table and gruoping by another and make sum equal

Question

There are 2 tables - DepoSevkDetay и SatisDetay . Both have columns - Miktar and UrunID . I need to make sum of Miktar in DepoSevkDetay for each UrunID equal to sum of Miktar in SatisDetay . Query I ve written cant handle it. What am I doing wrong? Considering that count of records in two tables is not equal

UPDATE
    Table_A
SET
    Table_A.[Miktar] = (((Table_B.Miktar)/Table_C.c) + 
(case when ((Table_B.Miktar) % Table_C.c  < Table_C.r) then 1 
                                                        else 0 end ))
FROM
    [Retail].[dbo].[tb_DepoSevkDetay] AS Table_A
    INNER JOIN (
                SELECT SUM(Miktar)as Miktar, UrunID
                FROM tb_SatisDetay
                GROUP BY UrunID ) AS Table_B
        ON Table_A.[UrunID] = Table_B.[UrunID]
    INNER JOIN (
                SELECT COUNT([UrunID]) AS c, ROW_NUMBER() OVER (ORDER BY UrunID) r, UrunID as UrunID
                FROM tb_DepoSevkDetay
                GROUP BY UrunID ) AS Table_C 
        ON Table_B.[UrunID] = Table_C.[UrunID]

Answer 1

I would do it like this. First, I would make Miktar=0:

UPDATE [Retail].[dbo].[tb_DepoSevkDetay]
SET [Miktar] = 0

Then I would update all records but first with the Miktar equal to sum(Miktar)/(Count(*))

; with Table_A as (
 SELECT *,
 ROW_NUMBER() OVER (PARTITION BY UrunID ORDER BY UrunID) as rn,
 COUNT(*) OVER (PARTITION BY UrunID) as c
 [Retail].[dbo].[tb_DepoSevkDetay])
UPDATE
    Table_A
SET
    Table_A.[Miktar] = Table_B.Miktar/(Table_A.c)
FROM
    Table_A
    INNER JOIN (
                SELECT SUM(Miktar)as Miktar, UrunID
                FROM tb_SatisDetay
                GROUP BY UrunID ) AS Table_B
        ON Table_A.[UrunID] = Table_B.[UrunID]
WHERE Table_A.c > 0 and Table_A.rn > 1

And then I would update the remaining [Miktar]'s, like this:

UPDATE
    Table_A
SET
    Table_A.[Miktar] = Table_B.Miktar - Table_C.Miktar
FROM
    [Retail].[dbo].[tb_DepoSevkDetay] AS Table_A
    INNER JOIN (
                SELECT SUM(Miktar)as Miktar, UrunID
                FROM tb_SatisDetay
                GROUP BY UrunID ) AS Table_B
        ON Table_A.[UrunID] = Table_B.[UrunID]
    INNER JOIN (
                SELECT SUM(Miktar)as Miktar, UrunID
                FROM [Retail].[dbo].[tb_DepoSevkDetay]
                GROUP BY UrunID ) AS Table_C
        ON Table_A.[UrunID] = Table_C.[UrunID]
WHERE Table_A.[Miktar] = 0

Hopefully, it makes sense

Answer 2

your requirement is not very clear.

Explain with one example

update dd
set Miktar=sd.Miktar
DepoSevkDetay DD
inner join
(select UrunID, sum(Miktar) Miktar
from SatisDetay
group by UrunID)SD
on dd.UrunID=sd.UrunID