Instruction
Good job! Even though we already computed the final ratio in step 2, we typically also want to round the ratio to a given number of decimal places. To that end, we can use the ROUND(value, decimal_places) function. Take a look:
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), 2) AS ShippedRatio
FROM Orders;
We surrounded the last column with the ROUND(..., 2) function invocation. Because the second argument is 2, we'll get the ratio rounded to two decimal places.
Exercise
Modify the template code. Round the ratio from the DiscountedRatio column to three decimal places.
Stuck? Here's a hint!
Wrap your division with a call to ROUND(..., 3).




