Question

When you have a subquery inside of the main query, which query is executed first?

a) Main query
b) Subquery
c) Both queries are executed simultaneously.
d) It depends on the database system.

Answer 1

The subquery is executed first when it is inside the main query.

Step-by-step explanation:

When you have a subquery inside of the main query, the subquery is executed first. The result of the subquery is then used by the main query to produce the final result set. For example, let's say we have a main query that selects all students from a table who have a score greater than the average score. The subquery within the main query calculates the average score. This subquery is executed first to obtain the average score, and then the main query uses this result to retrieve the required students. So, the correct answer to your question is b) Subquery - the subquery is executed first.