Attackers use the operator to append their own data to your query results. By using a non-existent ID like -9108 , they ensure the original data is hidden, leaving only their injected values (the 34,34 ) visible. The # at the end simply comments out the rest of your original code to prevent syntax errors.
This code snippet, -9108 UNION ALL SELECT 34,34# , is a classic example of syntax used for testing vulnerabilities in a database. -9108 UNION ALL SELECT 34,34#
Here are three post drafts tailored for different audiences. Option 1: Educational (Cybersecurity 101) Attackers use the operator to append their own