Section 1
1. Subqueries are limited to four per SQL transaction. True or False? Mark for Review
(1) Points
True
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
True
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
( Vrei sa traduci ceva?Want to translate something? http://translate.google.ro/# )
Niciun comentariu:
Trimiteți un comentariu