Group By X)a)-- Qkgc - {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

The attacker isn't trying to delete data yet; they are trying to "fingerprint" the database.

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. The attacker isn't trying to delete data yet;

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. never as executable code. like usernames

like usernames, hashed passwords, or emails. How to Prevent It or emails. How to Prevent It