Question

Table 1:

ID      Total1 Total2 Total3
1         10       0          20
1         40       0          50
1         15       0          5

Table 2:

ID     Total

1        140

How do i add cumulatively all the rows and find the matching total in table2?

How do i add cumulatively all the rows and find the NOT matching total in table2 and write update statement to update (add those) and write to table2 ?

select sum(t1.total1) + sum(t1.total2) +sum(t1.total3) as "Total" from
table t1, table t2 where t1.ID=t2.ID and  sum(t1.total1) +
sum(t1.total2) +sum(t1.total3)=t2.total;

I am not able to get it correctly the update syntax.

Answer 1

Looks like you have the right query to find the totals and match them up. To update rows that don’t have the same total, you could use a correlated subquery like this:

UPDATE table2
SET total = (
   SELECT SUM(Total1 + Total2 + Total3) FROM table1
   WHERE id = table2.id
   GROUP BY id
)

Or with a join (slightly more complicated, but likely faster)

UPDATE t2
SET t2.total = t1.total
FROM table2 t2
INNER JOIN (
   SELECT id, SUM(Total1 + Total2 + Total3) as total FROM table1
   GROUP BY id
) t1 ON t1.id = t2.id
WHERE t2.total <> t1.total