The ISNULL() function
The COALESCE() function
The NULLIF() function
Instruction
You can also use COALESCE() in calculations:
SELECT COALESCE(Price, 0) * 1.05 FROM Product;
The above query will return each product's price times 1.05 (if there's a price value) or a zero if the price is NULL.
Exercise
The company is giving a 10% discount on all prices. Show the names of all products, their current price, and the new discounted price. Name the new column NewPrice. If there is no price, show 0.0 in the NewPrice column.
Stuck? Here's a hint!
You can use the following piece of code to get the right price:
COALESCE(Price * 0.9, 0.0)
