🌱BeginnerFiltering & Sorting
BETWEEN, Column Aliases, and Table Aliases
Use BETWEEN for range checks and AS aliases for readable queries.
Overview
BETWEEN provides an inclusive range check: val BETWEEN low AND high is equivalent to val >= low AND val <= high. It works on numbers, dates, and strings. NOT BETWEEN excludes the range.
Aliases (AS) give a temporary name to columns or tables. Column aliases appear in result headers and can be used in ORDER BY. Table aliases shorten table names and are required when joining a table to itself (self-join). The AS keyword is optional you can write col alias or table_name alias directly.
Key Points
- •BETWEEN low AND high inclusive on both ends
- •NOT BETWEEN the inverse: outside the range
- •Column alias: SELECT price * 1.1 AS price_with_tax
- •Column alias usable in ORDER BY but not WHERE
- •Table alias: FROM orders o shorten long names
- •Table alias required for self-joins
Examples
BETWEEN for ranges
-- Numeric range (inclusive)
SELECT * FROM products WHERE price BETWEEN 10 AND 50;
-- Date range
SELECT * FROM orders
WHERE created_at BETWEEN '2024-01-01' AND '2024-12-31';
-- NOT BETWEEN
SELECT * FROM products WHERE price NOT BETWEEN 10 AND 100;Column and table aliases
-- Column alias
SELECT
first_name || ' ' || last_name AS full_name,
salary * 12 AS annual_salary,
UPPER(department) AS dept
FROM employees;
-- Table alias (shorter)
SELECT o.id, o.total, c.name AS customer
FROM orders o
JOIN customers c ON c.id = o.customer_id;Exercises
Write SQL to solve each exercise. Your progress is saved automatically.
Loading editor…
Completed: 0 / 5 exercises
Knowledge Check
Question 1 of 4