duminică, 4 aprilie 2010

Test: Quiz: Single-Row Subqueries

Section 1

1. Subqueries are limited to four per SQL transaction. True or False? Mark for Review
(1) Points


False (*)

2. In a non-correlated subquery, the outer query always executes prior to the inner query's execution. True or False? Mark for Review
(1) Points


False (*)

3. Single row subqueries may not include this operator: Mark for Review
(1) Points

ALL (*)




4. The result of this statement will be:

SELECT last_name, job_id, salary, department_id
FROM employees
WHERE job_id =
(SELECT job_id
FROM employees
WHERE employee_id = 141) AND department_id =
(SELECT department_id
FROM departments
WHERE location_id =1500)
Mark for Review
(1) Points

All employees from Location 1500 will be displayed

An error since you canメt get data from two tables in the same subquery

All employees with the department id of 141

Only the employees whose job id matches employee 141 and who work in location 1500 (*)

5. If the subquery returns no rows will the outer query return any values? Mark for Review
(1) Points

No, because you are not allowed to not return any rows from a subquery

Yes. It will just run and ignore the subquery

No, because the subquery will be treated like a null value. (*)

Yes, Oracle will find the nearest value and rewrite your statement implicitly when you run it


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