带分组的SQL更新

Question

Ok i have had a look through some questions on updating with a group by and found sql doesnt do it but i cant figure out how to perform an update on this particular query.

I have a cashbook with a load of transactions on and they match up to a bank statement but the problem is the bank statement is an aggregated value, so i need to group by the amount on the transactions in particular ways and match on these summed values. Once there is a positive match i then need to update each of those rows in that group on the cashbook to be reconciled.

What i have done so far is to get the correct grouping and then do an inner join to the bank statment to bring back all the values that match but obviously dont know how to update these rows....

Anyone got any ideas?

Thanks

Answer 1

You can store your results in a temporary table (CREATE TEMPORARY TABLE in MySQL) and then use it to filter your update.

SELECT id, name, firstname INTO #tmp FROM stuff;
UPDATE other SET count='new value' WHERE id IN (SELECT id FROM #tmp);

The Syntax maybe wrong since I don't use MSSQL

Answer 2

If I understand you correctly, you can determine the users to update using a select query and then just update these. I think the following query does what you intend:

with toupdate as (select userid
                  from (select userid, sum(value) as sumvalue
                        from cashbook cb
                        group by userid
                       ) join
                       bankstatement bs
                       on cb.userid = bs.userid 
                  where cb.sumvalue = bs.value
                 )
update cashbook
    set reconciled = 1
from toupdate
where cashbook.userid = toupdaqte.userid