-1469 Union All Select 34,34# Official

: This operator combines the results of two different SELECT statements into a single result set.

: This is a dummy value. By using a negative or non-existent ID, the attacker ensures the first part of the query returns no results, making room for the injected data to show up. -1469 UNION ALL SELECT 34,34#

Are you looking to write a on how to prevent these attacks, or more of a beginner's overview of web security? : This operator combines the results of two