Master SQL for Data Analysis - Common Table Expressions (CTEs)

The video tutorial explains Common Table Expressions (CTE) in SQL, highlighting their advantages over subqueries for improving readability and organization of code. It covers the steps to define a CTE, using the 'WITH' keyword, and provides examples of how CTEs can be used in queries. The tutorial also demonstrates using CTEs with user data and window functions to retrieve specific data, such as the top five oldest users.

What is the primary advantage of using CTEs over subqueries?

• CTEs are faster to execute.

• CTEs provide better readability and organization.

• CTEs require less memory.

• CTEs are more secure.

Which keyword is used to start a CTE in SQL?

• SELECT

• FROM

• JOIN

• WITH

In the example provided, what is calculated using the CTE for books?

• Minimum publication year

• Maximum price of books

• Average rating per book

• Total number of books

What function is used in the advanced CTE example to partition data?

• AVG

• ROW_NUMBER

• SUM

• COUNT

What is the goal of the query in the advanced CTE example?

• To list all users alphabetically

• To calculate the average age of users

• To find the youngest users

• To retrieve the top five oldest users