How many levels can subqueries be nested in a FROM clause?
Answers were Sorted based on User's Feedback
Answer / vikas trivedi
32 levels of nesting within a query is possible.
Is This Answer Correct ? | 36 Yes | 12 No |
Answer / pradeep
http://download.oracle.com/docs/cd/B19306_01/server.102/b142
00/queries007.htm
The below stated on above page from oracle
A subquery can contain another subquery. Oracle Database
imposes no limit on the number of subquery levels in the
FROM clause of the top-level query. You can nest up to 255
levels of subqueries in the WHERE clause.
Is This Answer Correct ? | 8 Yes | 1 No |
Answer / slokh
FROM clause
A subquery can also be found in the FROM clause. These are
called inline views.
For example:
select suppliers.name, subquery1.total_amt
from suppliers,
(select supplier_id, Sum(orders.amount) as total_amt
from orders
group by supplier_id) subquery1,
where subquery1.supplier_id = suppliers.supplier_id;
In this example, we've created a subquery in the FROM
clause as follows:
(select supplier_id, Sum(orders.amount) as total_amt
from orders
group by supplier_id) subquery1
This subquery has been aliased with the name subquery1.
This will be the name used to reference this subquery or
any of its fields.
Limitations:
Oracle allows an unlimited number of subqueries in the FROM
clause.
Is This Answer Correct ? | 10 Yes | 5 No |
Answer / shekaran04
Oracle imposes no limit on the number of SUB Queries levels
in the from clause
Is This Answer Correct ? | 5 Yes | 3 No |
Answer / sulochana
There is no limit on the no.of sub queries in the FROM clause.
in WHERE clause ,we can write upto 255 levels only..
Thanks & Regards,
Sulochana
Is This Answer Correct ? | 5 Yes | 3 No |
Answer / john
32 number of Subquery
http://msdn.microsoft.com/en-us/library/ms143432.aspx
Is This Answer Correct ? | 3 Yes | 3 No |
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