meet it

The database can do your sums, row by row.

Put a in SELECT and the database works it out for every row. Use + and -, * to multiply and / to divide. Here, each snack's price is worked out for a pack of 3.

The top line of the result shows the calculation itself, like price * 3, because that column has no name of its own yet.

Watch out with /. These prices are integers: whole numbers. Divide one whole number by another and SQL throws the leftover away. Write a , like 100.0, to keep it.

SELECT name, price * 3 FROM snacks;

7 / 2 gives 3, but 7 / 2.0 gives 3.5.

guess first

Pence into pounds. What will this show?

Guess before you run it. Wrong guesses are how you learn, and nothing is marked.

SELECT name, price / 100 FROM snacks WHERE name = 'chocolate';

your turn

Your turn. Buy snacks for a party.

Type how many friends are coming in the blank. The query works out what each snack costs, in pence, if everyone gets one.

Your code

result

Your answer appears here as a table.

fix it

Half price lost half a penny. Can you fix it?

Broken code to fix

result

Your answer appears here as a table.

Half of 95 is 47.5. Where did the .5 go?
Both 95 and 2 are whole numbers, so SQL throws the leftover away.
Change 2 to 2.0, then press run.

nailed it

you made the database do your sums. :D

Put calculations in SELECT with +, -, * and /.
The database works the sum out for every row.
Whole numbers divide to whole numbers. Use 2.0 to keep decimals.

new words in your collection

calculation
integer
decimal

This lesson isn’t saved. A free account remembers every lesson you finish.