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 Group By X)a)--

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?

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.

The attacker isn't trying to delete data yet; they are trying to "fingerprint" the database. Extract table names and column structures

Ensure your database user account only has the permissions it absolutely needs. For example, a "read-only" web user shouldn't be allowed to access INFORMATION_SCHEMA .

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. For example, a "read-only" web user shouldn't be

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.

The snippet you provided is a classic example of an attack. you use placeholders ( ? ).

If you are a developer, you can stop these attacks using three main methods: