Comparisons with NULL
Functions with NULL
COALESCE to the rescue
Instruction
Good. You can also use COALESCE in calculations in a similar way:
COALESCE(price, 0) * 1.05
The above query will return the price times 1.05 or 0 (0 * 1.05 = 0) if the price is NULL.
Exercise
The company organized a discount campaign on all prices: -10%.
Show the names of all products together with their price and the new prices (name the column new_price). If there is no price, show 0.00 in the column new_price. Round the result to two decimal points.
Stuck? Here's a hint!
To round your price to two decimal points, you can use the ROUND() function in the following way:
ROUND(price, 2)
To get the right price, you can write:
COALESCE(price * 0.9, 0.00)
