The application provides a search or filter field (often a user search). When you input a common character like a single quote ( ' ), you may see a database error or a change in behavior, indicating the input is not being sanitized before being placed into a SQL query. 2. Determine the Number of Columns
For this specific challenge, the goal is often to enumerate the database schema. If standard injection fails, try encoding the space characters or the keywords themselves.
Try searching for: %' UNION SELECT note FROM notes WHERE user_id=1 --
: Use modern Object-Relational Mapping libraries that handle escaping automatically.