LENGTH and CHAR_LENGTH in SQL - Mini Project: Build & Apply

Using LENGTH and CHAR_LENGTH to Measure Text in SQL

📖 Scenario: You work at a bookstore database. You want to find out how long the book titles are in terms of characters. This helps in formatting the display on the website.

🎯 Goal: Build SQL queries that use LENGTH and CHAR_LENGTH functions to measure the length of book titles.

📋 What You'll Learn

Create a table called books with columns id (integer) and title (text).

Insert three books with exact titles: 'SQL Basics', 'Learn SQL in 24 Hours', and 'Advanced SQL Techniques'.

Write a query to select each book's title and the length of the title using LENGTH(title).

Write a query to select each book's title and the character length of the title using CHAR_LENGTH(title).

💡 Why This Matters

🌍 Real World

Measuring text length helps format UI elements and validate input sizes in real applications like websites and apps.

💼 Career

Knowing LENGTH and CHAR_LENGTH is useful for database developers and analysts to handle text data correctly.

1

Create the books table and insert data

Create a table called books with columns id as integer and title as text. Then insert these exact rows: (1, 'SQL Basics'), (2, 'Learn SQL in 24 Hours'), and (3, 'Advanced SQL Techniques').

SQL

-- Create the books table and insert the three books
-- Your code here

Need a hint?

Use CREATE TABLE to make the table and INSERT INTO to add rows.

2

Add a query to measure length using LENGTH()

Write a SQL query that selects title and the length of the title using LENGTH(title) from the books table.

SQL

CREATE TABLE books (id INTEGER, title TEXT);
INSERT INTO books (id, title) VALUES
(1, 'SQL Basics'),
(2, 'Learn SQL in 24 Hours'),
(3, 'Advanced SQL Techniques');

-- Write a query selecting title and LENGTH(title)
-- Your code here

Need a hint?

Use SELECT title, LENGTH(title) FROM books; to get the length of each title.

3

Add a query to measure length using CHAR_LENGTH()

Write a SQL query that selects title and the character length of the title using CHAR_LENGTH(title) from the books table.

SQL

CREATE TABLE books (id INTEGER, title TEXT);
INSERT INTO books (id, title) VALUES
(1, 'SQL Basics'),
(2, 'Learn SQL in 24 Hours'),
(3, 'Advanced SQL Techniques');

SELECT title, LENGTH(title) FROM books;

-- Write a query selecting title and CHAR_LENGTH(title)
-- Your code here

Need a hint?

Use SELECT title, CHAR_LENGTH(title) FROM books; to get the character length of each title.

4

Complete the project with both queries

Ensure your SQL script includes the table creation, data insertion, and both queries: one using LENGTH(title) and one using CHAR_LENGTH(title).

SQL

CREATE TABLE books (id INTEGER, title TEXT);
INSERT INTO books (id, title) VALUES
(1, 'SQL Basics'),
(2, 'Learn SQL in 24 Hours'),
(3, 'Advanced SQL Techniques');

SELECT title, LENGTH(title) FROM books;

SELECT title, CHAR_LENGTH(title) FROM books;

-- Finalize your SQL script here
-- Your code here

Need a hint?

Make sure all parts are included in your final SQL script.