1Z0-006 SQL Fundamentals & Data Manipulation 3

Question 1

What does the TRUNCATE TABLE command do that differs from DELETE?

Accepted Answer

TRUNCATE is a DDL statement that removes all rows and cannot be rolled back in the same way as DELETE

Answer

TRUNCATE is a DDL operation that deallocates table data quickly and, unlike DELETE, implicitly commits and cannot be rolled back.

Question 2

Which operator tests whether a value falls within an inclusive range in a WHERE clause?

Accepted Answer

BETWEEN low AND high

Answer

BETWEEN low AND high is inclusive on both ends, equivalent to col >= low AND col <= high.

Question 3

Which SELECT statement retrieves distinct department IDs from the employees table?

Accepted Answer

SELECT DISTINCT department_id FROM employees;

Answer

DISTINCT is the standard SQL keyword to eliminate duplicate rows from a result set.

Question 4

What is the result of: SELECT 100 + NULL FROM dual;

Accepted Answer

NULL

Answer

Any arithmetic operation involving NULL propagates NULL as the result.

Question 5

Which SQL keyword is used to sort query results in descending order?

Accepted Answer

ORDER BY column DESC

Answer

ORDER BY column DESC instructs Oracle to sort the specified column from highest to lowest.

(1Z0-006) Oracle Database Foundations Associate Practice Test