Question

i need help in updating a balance column in table. using update command

The balance column in present in customer_master

customer_master > custcode,balance

It needs to be updated on the basis of values in two tables

Bookings > custcode, bookingamount

Receivables > custcode, amountrecd

for a customercode, the Balance is bookingamount – amountrecd

The command is to be applied in mysql and postgresql.

It can be for a single customer like (for custcode =’A1234XXXXX’) and also may be applied for all customers present in customer_master.

I tried Google on ‘Updating balance from two tables’ but with no luck so far.

thanks

Answer 1

my take which is sort of (possibly) over the top belt and braces

UPDATE  customer_master a
        LEFT JOIN (select custcode, sum(COALESCE(bookingamount, 0)) AS bookingamount 
                   from bookings group by custcode) b
            ON a.custcode = b.custcode
        LEFT JOIN (select custcode, sum(COALESCE(amountrecd, 0)) AS amountrecd 
                   from receivables group by custcode) c
            ON a.custcode = c.custcode
SET     
         a.balance = COALESCE(b.bookingamount, 0) - COALESCE(c.amountrecd, 0) 
-- WHERE a.custcode = 'A1234XXXXX'