WHERE with BETWEEN range in SQL - Mini Project: Build & Apply

Filter Products by Price Range Using WHERE with BETWEEN

📖 Scenario: You are managing a small online store database. You want to find products within a specific price range to create a special discount list.

🎯 Goal: Build a SQL query that selects products priced between two given values using the WHERE clause with BETWEEN.

📋 What You'll Learn

Create a table called products with columns id, name, and price.

Insert exactly these products with prices: (1, 'Pen', 5), (2, 'Notebook', 15), (3, 'Backpack', 45), (4, 'Calculator', 55), (5, 'Desk Lamp', 35).

Define two variables min_price and max_price with values 10 and 40 respectively.

Write a SQL query that selects name and price from products where price is between min_price and max_price.

💡 Why This Matters

🌍 Real World

Filtering products by price range is common in online stores to show customers affordable options or special deals.

💼 Career

Knowing how to use WHERE with BETWEEN helps database professionals write efficient queries for filtering data based on ranges.

1

Create the products table and insert data

Write SQL statements to create a table called products with columns id (integer), name (text), and price (integer). Then insert these exact rows: (1, 'Pen', 5), (2, 'Notebook', 15), (3, 'Backpack', 45), (4, 'Calculator', 55), and (5, 'Desk Lamp', 35).

SQL

-- Create table products and insert data
-- Your code here

Hint

Use CREATE TABLE to define the table and INSERT INTO with multiple rows to add the products.

2

Define price range variables

Write SQL statements to define two variables called min_price and max_price with values 10 and 40 respectively. Use SET statements for this purpose.

SQL

CREATE TABLE products (id INTEGER, name TEXT, price INTEGER);
INSERT INTO products (id, name, price) VALUES
(1, 'Pen', 5),
(2, 'Notebook', 15),
(3, 'Backpack', 45),
(4, 'Calculator', 55),
(5, 'Desk Lamp', 35);
-- Define min_price and max_price variables
-- Your code here

Hint

Use SET variable_name = value; to define variables in SQL.

3

Write the SELECT query with WHERE and BETWEEN

Write a SQL SELECT statement to get the name and price columns from the products table where the price is between the variables min_price and max_price. Use the WHERE clause with BETWEEN.

SQL

CREATE TABLE products (id INTEGER, name TEXT, price INTEGER);
INSERT INTO products (id, name, price) VALUES
(1, 'Pen', 5),
(2, 'Notebook', 15),
(3, 'Backpack', 45),
(4, 'Calculator', 55),
(5, 'Desk Lamp', 35);

SET @min_price = 10;
SET @max_price = 40;
-- Write SELECT query with WHERE price BETWEEN min_price AND max_price
-- Your code here

Hint

Use SELECT columns FROM table WHERE column BETWEEN value1 AND value2; syntax.

4

Complete the query with ORDER BY price ascending

Add an ORDER BY clause to the previous SELECT query to sort the results by price in ascending order.

SQL

CREATE TABLE products (id INTEGER, name TEXT, price INTEGER);
INSERT INTO products (id, name, price) VALUES
(1, 'Pen', 5),
(2, 'Notebook', 15),
(3, 'Backpack', 45),
(4, 'Calculator', 55),
(5, 'Desk Lamp', 35);

SET @min_price = 10;
SET @max_price = 40;

SELECT name, price FROM products WHERE price BETWEEN @min_price AND @max_price
-- Add ORDER BY price ascending
-- Your code here

Hint

Use ORDER BY column_name ASC to sort results in ascending order.

Practice

1. What does the SQL clause WHERE column BETWEEN 10 AND 20 do?

easy

A. Selects rows where the column value is greater than 10 but less than 20, excluding 10 and 20

B. Selects rows where the column value is between 10 and 20, including 10 and 20

C. Selects rows where the column value is exactly 10 or exactly 20 only

D. Selects rows where the column value is less than 10 or greater than 20

Solution

1. Step 1: Understand BETWEEN clause behavior

   The BETWEEN clause includes both the start and end values in the range.

2. Step 2: Apply to the given range 10 to 20

   This means values equal to 10, 20, or any number between them are selected.

3. Final Answer:

   Selects rows where the column value is between 10 and 20, including 10 and 20 -> Option B

4. Quick Check:

   BETWEEN includes boundaries = B [OK]

Hint: BETWEEN includes both start and end values [OK]

Common Mistakes:

• Thinking BETWEEN excludes boundary values
• Confusing BETWEEN with > and < operators
• Assuming BETWEEN works only with numbers

2. Which of the following is the correct syntax to select rows where age is between 18 and 30?

easy

A. SELECT * FROM users WHERE age BETWEEN (18 AND 30);

B. SELECT * FROM users WHERE age BETWEEN 18 TO 30;

C. SELECT * FROM users WHERE age BETWEEN 18, 30;

D. SELECT * FROM users WHERE age BETWEEN 18 AND 30;

Solution

1. Step 1: Recall correct BETWEEN syntax

   The correct syntax uses BETWEEN start AND end without commas or parentheses.

2. Step 2: Check each option

   SELECT * FROM users WHERE age BETWEEN 18 AND 30; uses correct syntax: BETWEEN 18 AND 30. Others have syntax errors.

3. Final Answer:

   SELECT * FROM users WHERE age BETWEEN 18 AND 30; -> Option D

4. Quick Check:

   BETWEEN ... AND ... syntax = D [OK]

Hint: BETWEEN always uses AND, never TO or commas [OK]

Common Mistakes:

• Using TO instead of AND
• Adding commas between values
• Using parentheses around BETWEEN clause

3. Given the table products with a column price, what rows will this query return?

SELECT * FROM products WHERE price BETWEEN 50 AND 100;

Assume the prices in the table are: 45, 50, 75, 100, 120.

medium

A. Rows with prices 50, 75, and 100

B. Rows with prices 45, 50, 75, 100, and 120

C. Rows with prices 75 and 100 only

D. Rows with prices 50 and 100 only

Solution

1. Step 1: Identify the range in BETWEEN clause

   The query filters prices between 50 and 100, including both 50 and 100.

2. Step 2: Check which prices fall in this range

   Prices 50, 75, and 100 are within the range; 45 and 120 are outside.

3. Final Answer:

   Rows with prices 50, 75, and 100 -> Option A

4. Quick Check:

   BETWEEN includes boundaries, so 50 and 100 included = A [OK]

Hint: BETWEEN includes start and end values in results [OK]

Common Mistakes:

• Excluding boundary values 50 and 100
• Including values outside the range like 45 or 120
• Confusing BETWEEN with > and < operators

4. Identify the error in this SQL query:

SELECT * FROM orders WHERE order_date BETWEEN '2023-01-01' TO '2023-01-31';

medium

A. Using TO instead of AND in BETWEEN clause

B. Dates should not be in quotes

C. BETWEEN cannot be used with dates

D. Missing semicolon at the end

Solution

1. Step 1: Check BETWEEN syntax

   BETWEEN requires AND between the two values, not TO.

2. Step 2: Validate other parts

   Dates in quotes are correct, BETWEEN works with dates, and semicolon is optional in many systems.

3. Final Answer:

   Using TO instead of AND in BETWEEN clause -> Option A

4. Quick Check:

   BETWEEN uses AND, not TO = A [OK]

Hint: BETWEEN always uses AND, never TO [OK]

Common Mistakes:

• Replacing AND with TO in BETWEEN
• Thinking dates can't be quoted
• Assuming semicolon is mandatory

5. You want to select employees hired between January 1, 2020, and December 31, 2022, inclusive. Which query correctly uses BETWEEN and also excludes employees hired on weekends?

SELECT * FROM employees WHERE hire_date BETWEEN '2020-01-01' AND '2022-12-31' AND EXTRACT(DOW FROM hire_date) NOT IN (0,6);

What does this query do?

hard

A. Selects employees hired between the dates including weekends

B. Selects employees hired only on weekends between the dates

C. Selects employees hired between the dates excluding weekends

D. Syntax error due to EXTRACT usage

Solution

1. Step 1: Understand BETWEEN usage

   The query selects employees hired from 2020-01-01 to 2022-12-31 inclusive.

2. Step 2: Analyze EXTRACT(DOW FROM hire_date) condition

   EXTRACT(DOW) returns day of week (0=Sunday, 6=Saturday). NOT IN (0,6) excludes weekends.

3. Step 3: Combine conditions

   Only employees hired on weekdays within the date range are selected.

4. Final Answer:

   Selects employees hired between the dates excluding weekends -> Option C

5. Quick Check:

   BETWEEN + weekday filter = C [OK]

Hint: Use BETWEEN for range and filter weekdays with EXTRACT [OK]

Common Mistakes:

• Assuming BETWEEN excludes boundaries
• Confusing day numbers for weekend days
• Thinking EXTRACT causes syntax error