The following SQL statement contains which type of subquery?
SELECT title,retail,category,cataverage FROM books NATURAL JOIN
(SELECT category,AVG(retail)cataverage FROM books GROUP BY category);
A) single-row
B) multiple-row
C) correlated
D) uncorrelated

Question

​The following SQL statement contains which type of subquery?
​ SELECT title,retail,category,cataverage FROM books NATURAL JOIN
(SELECT category,AVG(retail)cataverage FROM books GROUP BY category);
A) ​single-row
B) ​multiple-row
C) ​correlated
D) ​uncorrelated

Quizplus · Accepted Answer

This is an uncorrelated subquery as it is not referencing any column from the outer query. It is simply calculating the average retail price for each category and returning a result set that is joined with the main Books table.

​The Following SQL Statement Contains Which Type of Subquery

The Following SQL Statement Contains Which Type of Subquery