: If the page displays the number "34" several times, it confirms the site is vulnerable to SQL injection.
: In MySQL, this symbol marks the rest of the original query as a comment , effectively deleting the remaining code (like WHERE clauses or authentication checks) to bypass security. Purpose of This "Piece" -3216' UNION ALL SELECT 34,34,34,34#
: This operator combines the results of the original query with a new one. By using UNION ALL , the attacker can inject their own data into the results page. : If the page displays the number "34"
: This part creates a "fake" row of data. Attackers use this to determine the exact number of columns required for the UNION to work, as both queries must have the same number of columns. -3216' UNION ALL SELECT 34,34,34,34#