Hi all,

I happen to have an oracle quiz to answer at school and I completed it except this one very question:

I just don't know what to answer. I'd say there is no maximum, but I can't find anything confirming that anywhere, and I have no idea how to answer the "why".

Your thoughts would be much appreciated!

Rhetorical question -
can sub-select return more rows than exist within complete result set?
Please justify your response.

Depends on the WHERE condition. Look at this:
SELECT some_fields
FROM some_table
WHERE a_field = (sub_SELECT)

Then look at ORA-01427

Heh, are you saying that a subquery can return too many rows?

Yeah I understand it's because of the "=" which means we're only allowed one row in this case.

But what if it was WHERE a_field in (sub_SELECT) ?

I mean, the sub select can return a full table so how do I know what is the maximum number of rows returned without any clue on the WHERE clause?

That's why I'm confused by this question :/

So you got the answer: it depends on the condition.

I got all the points on this question thx guys