Why prepared statements exist in SQL - See It in Action

Understanding Why Prepared Statements Exist

📖 Scenario: You are working on a small online bookstore database. You want to safely and efficiently search for books by their title.

🎯 Goal: Build a simple SQL query using prepared statements to safely search for books by title, preventing SQL injection and improving performance.

📋 What You'll Learn

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

Insert three specific books into the books table.

Write a prepared statement to select books by title using a placeholder.

Execute the prepared statement with a specific book title.

💡 Why This Matters

🌍 Real World

Prepared statements are used in web applications to safely handle user input in database queries, preventing attacks and improving speed.

💼 Career

Understanding prepared statements is essential for database developers, backend engineers, and anyone working with databases to write secure and efficient code.

1

Create the books table and insert data

Write SQL commands to create a table called books with columns id (integer), title (text), and author (text). Then insert these three books exactly: (1, 'The Great Gatsby', 'F. Scott Fitzgerald'), (2, '1984', 'George Orwell'), and (3, 'To Kill a Mockingbird', 'Harper Lee').

SQL

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

Need a hint?

Use CREATE TABLE to define the table and INSERT INTO to add each book.

2

Prepare a statement to select books by title

Write a SQL command to prepare a statement named find_book that selects all columns from books where the title equals a placeholder ?.

SQL

CREATE TABLE books (id INTEGER, title TEXT, author TEXT);
INSERT INTO books VALUES (1, 'The Great Gatsby', 'F. Scott Fitzgerald');
INSERT INTO books VALUES (2, '1984', 'George Orwell');
INSERT INTO books VALUES (3, 'To Kill a Mockingbird', 'Harper Lee');
-- Prepare the statement named find_book
-- Your code here

Need a hint?

Use PREPARE find_book FROM 'SELECT * FROM books WHERE title = ?' to create the prepared statement.

3

Execute the prepared statement with a book title

Write a SQL command to execute the prepared statement find_book with the parameter '1984'.

SQL

CREATE TABLE books (id INTEGER, title TEXT, author TEXT);
INSERT INTO books VALUES (1, 'The Great Gatsby', 'F. Scott Fitzgerald');
INSERT INTO books VALUES (2, '1984', 'George Orwell');
INSERT INTO books VALUES (3, 'To Kill a Mockingbird', 'Harper Lee');
PREPARE find_book FROM 'SELECT * FROM books WHERE title = ?';
-- Execute the prepared statement with '1984'
-- Your code here

Need a hint?

Use EXECUTE find_book USING '1984' to run the prepared statement with the title.

4

Deallocate the prepared statement

Write a SQL command to deallocate the prepared statement named find_book to free resources.

SQL

CREATE TABLE books (id INTEGER, title TEXT, author TEXT);
INSERT INTO books VALUES (1, 'The Great Gatsby', 'F. Scott Fitzgerald');
INSERT INTO books VALUES (2, '1984', 'George Orwell');
INSERT INTO books VALUES (3, 'To Kill a Mockingbird', 'Harper Lee');
PREPARE find_book FROM 'SELECT * FROM books WHERE title = ?';
EXECUTE find_book USING '1984';
-- Deallocate the prepared statement find_book
-- Your code here

Need a hint?

Use DEALLOCATE PREPARE find_book; to clean up the prepared statement.