SQL Injection Tutorial: All common SQL injection problems and Solutions

Hello readers of BTS,
    Today I'll write an tutorial for you what covers most problems while doing SQL injection and solutions to them. Probably every person who has looked at tutorials to hack a website have noticed that there are too much SQL tutorials. Almost every forum has 10 tutorials and blogs 5 tutorials about SQL injection, but actually those tutorials are stolen from somewhere

Google dork "Index of /sh3llZ" allows you to find shell uploaded by hackers

Usually hackers upload shell to victim's site using the vulnerability in that website. Shell allows hackers to hack/deface the website. Sometimes hackers left the shell in the vulnerable sites.  Here is simple google search allows you to find a shell uploaded by hackers.

Use one of the following google dork to find the shell:
intitle:index of/sh3llZ
"Index of /sh3llZ"
"/sh3llZ/uploadshell/