{keyword} Union All Select Null,null,null,null,null,null,null,null-- Ppsq Guide

: If the number of NULL values does not match the original query's column count, the server usually returns an error (like a 500 Internal Server Error).

: An attacker starts with one NULL and keeps adding more (e.g., NULL, NULL , then NULL, NULL, NULL ). : If the number of NULL values does

: When the number of NULL s matches exactly (in your case, 8 columns), the page will load normally or show an extra blank row, confirming the database structure. Why This Matters Why This Matters : Attackers use NULL because

: Attackers use NULL because it is compatible with almost every data type (integers, strings, dates), making it the "safest" way to avoid syntax errors while testing column counts. How it Works : This represents the original

Once an attacker knows there are 8 columns, they can replace the NULL values with commands to extract sensitive data, such as usernames, passwords, or database versions. SQL injection UNION attacks | Web Security Academy

: This is a SQL comment marker that tells the database to ignore the rest of the original query, preventing errors from leftover code. How it Works

: This represents the original input (like a product category or search term) that the application expects.