-1697 - Union All Select 34#

: This is a dummy value. By using a negative or non-existent ID, an attacker forces the original database query to return no results.

To prevent these types of attacks, developers should never insert user input directly into SQL queries. Instead, you should use: -1697 UNION ALL SELECT 34#

The string you've provided, "-1697 UNION ALL SELECT 34#" , is a classic example of a payload. This specific syntax is often used by security researchers or attackers to test if a database-driven website is vulnerable to unauthorized data access. What this string does: : This is a dummy value