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

: 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

: 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. : This is a SQL comment marker that

The primary goal of this specific syntax is to returned by the original, legitimate database query. : When the number of NULL s matches

: 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 SQL injection UNION attacks | Web Security Academy

: This command attempts to append a new set of results to the original query's output.

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