: This is a "fingerprint." The attacker concatenates strings to see if they appear on the webpage. If the user sees "qbqvqlhsxrmQErHqqbqq" on their screen, they know this specific column is vulnerable to data extraction.
The string you provided is a malicious SQL payload designed to extract information from a database. : This is a "fingerprint
This ensures the database treats the input as data, not executable code. not executable code.