Comparison Operators
The Comparison operators can compare one expression to another. The outcome is always true, false, or null. Usually, you use a comparison operators in conditional control statements and in the WHERE clause of the SQL data manipulation statements. Now there are a couple of examples as shown below:
IF quantity_on_hand > 0 THEN
UPDATE inventory SET quantity = quantity - 1
WHERE part_number = item_number;
ELSE
...
END IF;