How to update ms access database table using update and sum() function?

Question

I have Two tables in my access database

• table1(ID,productname,qunatity,remainder)
• table2(ID,productname,sales)

these tables are rela

Answer 1

When you say that it's linked by the productname field please tell me in table 1 that is a foreign key. Since you already have an ID in table 2 there's no reason not to use that ID as the foreign key in table 1.

If you were to do that the update would be as simple as this:

update table1 
set table1.quantity = table1.quantity - SUM( table2.sales ) 
from table1
inner join table2 on table1.productID = table2.productID
where table1.productID = 1;