Error:

You have an error in your sql syntax;
Check The Manual That CorreSponds To
Your MySQL Server Version for the
Right Syntax To Use Near ‘Key)
Values (‘user1’, ‘[email protected]’, ‘usrpsw’, ‘0’, ‘0’) ‘
AT LINE 1

Key int (11) field NULL (NO) DEFAULT 0

Answer 1, Authority 100%

$ sql = "insert Into League (User, Email, Password, Rival,` Key`)
           Values ('$ this- & gt; user', '$ this- & gt; email', '$ this- & gt; pass', '0', '0') ";

key and other reserved fields need to be taken in `