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

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

: 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). : This command attempts to append a new

: 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 represents the original input (like a

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

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