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

This specific string is designed to be appended to a vulnerable input field (the {KEYWORD} in your example) to probe the database structure: : Closes the original string literal in the SQL query.

The payload you provided, ' UNION ALL SELECT NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL-- , is a common pattern used in to determine the number of columns returned by an original database query. What this Payload Does This specific string is designed to be appended

: Appends a new set of results to the original query's output. ' UNION ALL SELECT NULL

NULL is used because it is compatible with almost any data type (string, integer, date, etc.), ensuring the query won't fail due to data type mismatches. This specific string is designed to be appended