How many levels can subqueries be nested in a FROM clause?
Answer Posted / 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 |
Post New Answer View All Answers
What is the primary use of normalization?
What is an escape character in sql?
Explain commit, rollback and savepoint.
why does the selected column have to be in the group by clause or part of an aggregate function? : Sql dba
What is a natural join sql?
Where is sql database stored?
Enlist the characteristics of pl/sql?
What is number function in sql?
how to increment dates by 1 in mysql? : Sql dba
What is cost in sql execution plan?
how to install mysql? : Sql dba
Difference between truncate, delete and drop commands?
How to convert comma separated string to array in pl/sql?
Which is better join or subquery?
What is trigger explain with example?