1Z0-071 Using Subqueries 2

Question 1

What is a correlated subquery?

Accepted Answer

A subquery that references a column from the outer query

Answer

A correlated subquery references a column from the outer query and is re-executed for each row of the outer query.

Question 2

Which error occurs when a single-row operator is used with a multi-row subquery result?

Accepted Answer

ORA-01427

Answer

ORA-01427 'single-row subquery returns more than one row' is raised when = or < is used against a multi-row subquery.

Question 3

A subquery in the FROM clause is called a:

Accepted Answer

Inline view

Answer

A subquery placed in the FROM clause is called an inline view because it acts like a temporary named table.

Question 4

What does the ALL operator do when used with a subquery?

Accepted Answer

Returns TRUE only if the condition is met for every row returned by the subquery

Answer

ALL requires the comparison to be true for every value returned by the subquery.

Question 5

Which subquery type returns exactly one row and one column?

Accepted Answer

Scalar subquery

Answer

A scalar subquery returns a single row and a single column and can be used wherever a single value is expected.

1Z0-071 - Oracle Database SQL Certified Associate Practice Test