Quick Answer

Handle special character issues.

Understanding the Issue

Occurs when SQL queries contain invalid or unescaped special characters.

The Problem

This code demonstrates the issue:

Sql Error 
SELECT * FROM users WHERE name = 'O�Reilly'; -- Smart quote error

The Solution

Here's the corrected code:

Sql Fixed 
-- Solution 1: Use proper quotes
SELECT * FROM users WHERE name = 'O''Reilly';

-- Solution 2: Parameterized queries
PREPARE stmt FROM 'SELECT * FROM users WHERE name = ?';
SET @name = 'O�Reilly';
EXECUTE stmt USING @name;

-- Solution 3: Escape characters
-- In PHP: mysqli_real_escape_string($conn, $name)

-- Solution 4: Check encoding
SET NAMES utf8mb4; -- For full Unicode support

Key Takeaways

Properly escape special characters or use parameters.