W3. SQL Avg

Question 1

Q: What does the SQL AVG() function do?

Answer 1

A: It returns the average value of a numeric column.

Question 2

Q: Write a query to find the average price in the “Price” column of the “Products” table.

Answer 2

SELECT AVG(Price) 
FROM Products;

Question 3

Q: Do AVG() calculations include NULL values?

Answer 3

A: No, NULL values are ignored in AVG() calculations.

Question 4

Q: What is the syntax for using AVG() with a condition?

Answer 4

SELECT AVG(column_name)
FROM table_name
WHERE condition;

Question 5

Q: Write a query to find the average price of products in category 1.

Answer 5

SELECT AVG(Price) 
FROM Products 
WHERE CategoryID = 1;

Question 6

Q: How can you give a descriptive name to the result column of AVG()?

Answer 6

A: Use the AS keyword to set an alias, e.g., AS [average price].

Question 7

Q: Write a query to find the average price in the “Products” table and label it as “average price.”

Answer 7

SELECT AVG(Price) AS [average price] 
FROM Products;

Question 8

Q: How do you list all records with a value higher than the average?

Answer 8

A: Use a subquery with AVG(), e.g., WHERE Price > (SELECT AVG(Price) FROM Products).

Question 9

Q: Write a query to return all products with a price higher than the average price.

Answer 9

SELECT * FROM Products 
WHERE Price > (SELECT AVG(Price) FROM Products);

Question 10

Q: How do you use AVG() with GROUP BY to find averages for each group?

Answer 10

A: Combine AVG() with GROUP BY, e.g., GROUP BY CategoryID.

Question 11

Q: Write a query to find the average price for each category in the “Products” table.

Answer 11

SELECT AVG(Price) AS AveragePrice, CategoryID 
FROM Products 
GROUP BY CategoryID;