Changing rows with UPDATE

UPDATE changes values in the rows that match a WHERE condition:

UPDATE product SET price = 0.95 WHERE code = 'P02';

SET lists the columns to change. You can change several at once, separated by commas: SET price = 0.95, in_stock = 150.

Always use WHERE

The WHERE decides which rows change. Leave it out and every row is updated:

UPDATE product SET price = 0;   -- changes ALL products!

So nearly every UPDATE should have a WHERE. The checker runs your UPDATE, then reads the table back to confirm only the right row changed.

Change the price of the product with code 'P02' to 0.95. Be sure to use a WHERE so only that product changes.

UPDATE product SET price = ... WHERE code = 'P02';

Click Run to see the output here.