CRT Database Management & SQL 3

Question 1

A tobacco shop wants to sort its cigar inventory by price from highest to lowest. Which ORDER BY clause achieves this?

Accepted Answer

ORDER BY price DESC

Answer

ORDER BY price DESC sorts results in descending (high-to-low) order.

Question 2

Which SQL keyword is used to update the price of a specific tobacco product already in the database?

Accepted Answer

UPDATE

Answer

The UPDATE statement modifies existing data in one or more rows of a table.

Question 3

A manager runs: SELECT brand, AVG(price) FROM products GROUP BY brand. What does this query return?

Accepted Answer

The average price for each brand

Answer

AVG() with GROUP BY calculates the average value of a column for each distinct group.

Question 4

Which SQL clause filters results AFTER an aggregation has been performed on a tobacco sales report?

Accepted Answer

HAVING

Answer

HAVING filters grouped results after aggregation, whereas WHERE filters individual rows before aggregation.

Question 5

In a retail POS database, what is a FOREIGN KEY used for?

Accepted Answer

Linking a column in one table to the primary key of another table

Answer

A FOREIGN KEY creates a referential link between tables, enforcing relational integrity.

(CRT) Certified Retail Tobacconist Practice Test