Microsoft SQL Server Development for Everyone - SQL COUNT Aggregate Function

The video tutorial covers using SQL to count the number of students enrolled per course. It begins with a basic query to select data from an enrollments table and explains the need for aggregate functions to count students. The tutorial highlights the importance of using GROUP BY with aggregate functions and demonstrates how to enhance query output by including additional columns and formatting. The video concludes with a practical example of generating a report suitable for administrative purposes.

What is the primary goal when counting students per course in SQL?

• To find the total number of courses

• To list all students in each course

• To calculate the average grade per course

• To determine the number of students enrolled in each course

Which SQL function is used to count the number of students per course?

• SUM

• COUNT

• AVG

• MAX

Why is the GROUP BY clause necessary when using aggregate functions?

• To filter the data

• To join tables

• To sort the results

• To group rows that have the same values in specified columns

What additional information is included in the enhanced query output?

• Enrollment dates

• Course codes and titles

• Instructor names

• Student names

What is the purpose of joining the courses table in the final query?

• To add student details

• To include course codes and titles

• To filter out specific courses

• To calculate the average number of students