{keyword} Union All Select Null,null,null,null,null,null,null,null-- Ppsq May 2026

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

: 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). Once an attacker knows there are 8 columns,

: An attacker starts with one NULL and keeps adding more (e.g., NULL, NULL , then NULL, NULL, NULL ). such as usernames