Day 5 – Grouping and Summarizing Query Results

For test exercise we’ll use the PizzaDB. You can find link to the database script on GIT.

You don’t need to have a database installed to do these exercise, just use the prompts below.

In these exercise we’ll write some queries using either the Product or Employee tables.

Exercise #1

What is the average price of a product by product type?

You can use the product table.  Display the ProductType and AveragePrice

/* Answer */
select ProductType, avg(Price) AveragePrice
from Product
group by ProductType

Hint: Use the AVG function to calculate the average.

Show the answer to see the query I wrote: Notice that I group by ProductType and the Price is an argument to the avg function.

Exercise #2

How may employees are there in the Employee table?

/* Answer */
select count(*)
from Employee

Hint: You can don’t need to use GROUP BY to answer this question.