Question

I’m using oracle(10).

I’ve got two tables as follows:

Table1 (uniq rows): ID    AMOUNT     DATE   Table2: ID    AMOUNT1 AMOUNT2 ...AMOUNTN DATE 

Table2 is connected many to one to Table1 connected via ID.

What I need is update-ing Table1.DATE with: the last (earliest) date from Table2 where Table1.AMOUNT – SUM(Table2.AMOUNT1) <= 0, when reading table 2 backwards by the Table2.DATE field.

Is there a simple way to do it?

Thanks in advance!

UPDATE: as I see from your answers I had misspecified the question a bit. So here goes a detailed example:

Table1 has:

ID: 1     AMOUNT:100    DATE:NULL 

Table2 has (for ID: 1 so ID is not listed in here):

AMOUNT1     DATE 50          20080131 30          20080121 25          20080111 20          20080101 

So in this case I need 20080111 as the DATE in Table1 as 50+30+25 => 100.

Answer 1

Based on your revised question, this is a case for using analytic functions.

Assuming you meant >=100 rather than <= 100 as your example implies, and renaming columns DATE to THEDATE since DATE is a reserved word in Oracle:

update table1 set thedate= ( select max(thedate) from   ( select id, thedate,            sum(amount1) over (partition by id  order by thedate desc) cumsum     from table2   ) v   where v.cumsum >= 100   and v.id = table1.id ) 

If the 100 means the current value of table1 then change that line to:

  where v.cumsum >= table1.amount