-1740) — Union All Select 34,34,34#

This tells the database to combine the results of the original query with a new query created by the attacker [3, 4].

If successful, this probe allows an attacker to: Map the database structure (column counts and data types). -1740) UNION ALL SELECT 34,34,34#

Attackers use repeating constants like this to determine the number of columns in the original table [3]. If the page loads without an error, they know the table has exactly three columns. This tells the database to combine the results

Sanitize inputs to reject special characters like ) , # , and SQL keywords in fields where they don't belong [8]. If the page loads without an error, they

High (Targeting database integrity and data exfiltration). 2. Technical Analysis

This is an attempt to "break out" of the original query logic by providing a non-existent ID and closing any open parentheses.