Chapter 4, Problem 14RQ

Explanation of Solution

Subquery:

Subquery means one query is placed inside with another query.

• The inner query is called a subquery.
• The subquery is calculated first.
  • After the subquery has been determined and the outer query can apply the results of the subquery.

Example:

The example for subquery is given below:

SELECT ORDER_NUMBER FROM ORDER_LINE WHERE BOOK_NUMBER IN(SELECT BOOK_NUMBER FROM BOOKS WHERE CATEGORY = 'CE');

Explanation:

The above query is used to list the order number using subquery...