{keyword} And (select 8148 From(select Count(*),concat(0x7162717671,(select (elt(8148=8148,1))),0x7171627171,floor(rand(0)*2))x From Information_schema.character_sets — Group By X)a)-- Qkgc

It uses functions like CONCAT and GROUP BY to intentionally trigger a duplicate-key error. The database's error message will then "leak" the information hidden inside the query (in this case, the results of the SELECT 1 or version info) back to the attacker's screen.

If a website's search bar or URL parameter isn't properly "sanitized," an attacker can use this method to: (e.g., MySQL, PostgreSQL). Extract table names and column structures. It uses functions like CONCAT and GROUP BY

These are hexadecimal representations of characters (like 'qbqvq') used as delimiters so the attacker can easily spot their "stolen" data in the middle of a messy error message. Why is it dangerous? Extract table names and column structures

This is the gold standard. Instead of building a query string with user input, you use placeholders ( ? ). The database treats the input strictly as data, never as executable code. This is the gold standard