lesson 05 Filtering & sorting · beginner

Combine conditions

Combine filters with AND, OR and parentheses.

the idea

AND requires both conditions. OR requires either. AND binds more tightly than OR, so parentheses make mixed conditions explicit.

tables in this lesson

The challenges use this data. Each column shows its type underneath; → marks a link to another table.

example

The idea in one query. Press Run to see what it returns; running examples never affects your progress.

SELECT name, price
FROM products
WHERE category = 'Tech' AND price < 100;

Watch for: Without parentheses, a price filter may apply to only one side of OR.

build it step by step

Each step changes one thing. Run them in order and watch the result change.

1. 1

   Require both conditions. Category and price are separate columns. AND keeps a row only when both are true.

   step-1.sql Run

   sql›

   SELECT name, category, price
   FROM products;

2. 2

   Run the reference. AND requires both conditions. OR requires either. AND binds more tightly than OR, so parentheses make mixed conditions explicit.

   step-2.sql Run

   sql›

   SELECT name, price
   FROM products
   WHERE category = 'Tech' AND price < 100;