lesson 04 Filtering & sorting · beginner

Comparisons & ranges

Filter numbers and dates with comparisons and ranges.

the idea

Use >, >=, < and <= to compare values. BETWEEN includes both endpoints. Decide whether the task includes the boundary before choosing an operator.

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 price >= 45;

Watch for: Using > instead of >= drops the boundary row.

build it step by step

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

1. 1

   Include the boundary. Look at the prices. A product at exactly 45 stays when the condition uses >=.

   step-1.sql Run

   sql›

   SELECT name, price
   FROM products
   ORDER BY price;

2. 2

   Run the reference. Use >, >=, < and <= to compare values. BETWEEN includes both endpoints. Decide whether the task includes the boundary before choosing an operator.

   step-2.sql Run

   sql›

   SELECT name, price
   FROM products
   WHERE price >= 45;