-1740) Union All Select 34,34,34# -

Extract sensitive information (usernames, passwords, PII) by replacing the constants with table names [1]. Bypass authentication mechanisms.

Implement parameterized queries immediately. This treats all user input as data, never as executable code [6, 7]. -1740) UNION ALL SELECT 34,34,34#

This is a comment character in MySQL used to nullify the rest of the original, legitimate query, preventing syntax errors [2, 5]. Extract sensitive information (usernames

This tells the database to combine the results of the original query with a new query created by the attacker [3, 4]. never as executable code [6

Sanitize inputs to reject special characters like ) , # , and SQL keywords in fields where they don't belong [8].