Instruction
Great work! We originally wanted to see a percentage, so let's modify our query a little bit to calculate a percentage instead of a ratio. Here's step 4:
SELECT
COUNT(CASE
WHEN ShippedDate IS NOT NULL
THEN OrderID
END) AS CountShipped,
COUNT(OrderID) AS CountAll,
ROUND(COUNT(CASE
WHEN ShippedDate IS NOT NULL
THEN OrderID
END) / CAST(COUNT(OrderID) AS float) * 100, 2) AS ShippedRatio
FROM Orders;
Note that we multiply the result of the the division inside the ROUND() function by 100 to get a percentage instead of a ratio.
Exercise
What is the percentage of discontinued items at Northwind? Show three columns: CountDiscontinued, CountAll, and PercentageDiscontinued. Round the last column to two decimal places.
Stuck? Here's a hint!
Use the Discontinued column from the Products table. Remember to cast the denominator to float and to multiply the result by 100 to get a percentage.




