There is a table like this:

I want to multiply Values where I have the same ID.

So that I get a table looking like this:

Unfortunately I have no point where to start for this that makes sense...

CodePudding user response：

There's a trick to doing that using exp, sum, and log.

select ID,  exp(sum(log(Value))) as Value
from t
group by ID

Fiddle

CodePudding user response：

Try this

SELECT id, (a.value * b.value) as sum
FROM tablename, tablename a
WHERE tablename.id = a.id