Select Null,null,null,null,null,null,null,null From Msysaccessobjects-- Udhz - {keyword}' Union All

Matches the number of columns in the original table. Attackers use NULL to figure out how many columns they need to match without causing a data type error [2, 3].

This is the gold standard. It treats user input as literal text, not executable code [6]. Matches the number of columns in the original table

Sources:[1] microsoft.com[2] portswigger.net[3] geeksforgeeks.org[4] sqlinjection.net[5] owasp.org[6] owasp.org It treats user input as literal text, not

The best way to stop these attacks is to never "glue" user input directly into your database queries. Instead, use: How to Prevent It: A system table in

Comments out the rest of the original query so it doesn't cause a syntax error [1, 5]. How to Prevent It:

A system table in Access that contains information about database objects. If successful, the attacker can see if they have access to system metadata [1, 4].

Are you working on or just curious about how these injection patterns work?