1Z0-006 Basic SQL Statements 3

Question 1

Which DELETE syntax correctly removes all rows from a table named EMPLOYEES?

Accepted Answer

DELETE FROM EMPLOYEES;

Answer

DELETE FROM table_name without a WHERE clause removes all rows while keeping the table structure intact.

Question 2

What does the ORDER BY clause do by default when no ASC or DESC is specified?

Accepted Answer

Sorts in ascending order

Answer

If neither ASC nor DESC is specified, ORDER BY sorts in ascending (ASC) order by default.

Question 3

Which aggregate function returns the number of non-NULL values in a column?

Accepted Answer

COUNT

Answer

COUNT(column_name) counts only non-NULL values in that column; COUNT(*) counts all rows including NULLs.

Question 4

Which SQL clause is used to join data from a column with the rows of another table inline?

Accepted Answer

SUBQUERY in FROM (inline view)

Answer

A subquery in the FROM clause (inline view) acts as a derived table that can be queried like a regular table.

Question 5

Which wildcard character in a LIKE condition matches any single character?

Accepted Answer

_

Answer

The underscore (_) wildcard matches exactly one character, while % matches zero or more characters.

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