[Klex789]

Hello friends, I have a few questions, I know sqli, I know the basics, but I have a few questions in my head, thank you very much to the friends who answer them, let me pass without much ado, for example, let's say there is a parameter “example.com/php?id=123” and another time-based parameter is “example. com/example/example” How can sqli be done to this parameter example. com/example/example'+if(benchmark(3000000,MD5(1)),NULL,NULL),NULL),NULL),NULL),NULL),NULL)%20%23 I know injections like this, but I want to go a little further and I want to know what's going on behind it, I want to be able to make sql injection on sites that are difficult, I want to know exactly sql injection, if you show me a way, thank you very much for clearing my thoughts about this way. regards