34# | -1697 Union All Select

: These can block common "UNION ALL" patterns before they ever reach your database.

: In MySQL, this character marks the rest of the query as a comment, effectively "breaking" any remaining original code that might cause the attack to fail. Why are you seeing this? -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: : These can block common "UNION ALL" patterns