变量声明：-
$firstname="";
$surname ="";
$id ="";
$faculty_of_study= "";
$enrolled_course ="";
$gender ="";
$password= "";
$telephone_no="";
$email_address="";
$sql="";
$firstname = addslashes($_POST["firstname"]);
$surname = addslashes($_POST["surname"]);
$id = addslashes($_POST["id"]);
$faculty_of_study = addslashes($_POST["faculty_of_study"]);
$enrolled_course = addslashes($_POST["enrolled_course"]);
$gender = addslashes($_POST["gender"]);
$password = addslashes($_POST["password"]);
$telephone_no = addslashes($_POST["telephone_no"]);
$email_address = addslashes($_POST["email_address"]);
$sql = "INSERT INTO people (firstname, surname, id,faculty_of_study, enrolled_course, gender, password, telephone_no, email_address); VALUES ("$firstname", "$surname", "$id", "$faculty_of_study", "$enrolled_course", "$gender","$password", "$telephone_no", "$email_address")";
语法错误 第 21 行出现意外的"$firstname"（T_VARIABLE
）
试试这个
$sql = "INSERT INTO people (firstname, surname, id,
faculty_of_study, enrolled_course, gender, password, telephone_no,
email_address) VALUES ('$firstname', '$surname', '$id',
'$faculty_of_study',
'$enrolled_course', '$gender','$password', '$telephone_no','$email_address')";
试试这个
$sql = "INSERT INTO people (firstname, surname, id,faculty_of_study, enrolled_course, gender, password, telephone_no, email_address) VALUES ('".$firstname."', '".$surname."', '".$id."', '".$faculty_of_study."', '".$enrolled_course."', '".$gender."','".$password."', '".$telephone_no."', '".$email_address."')";
并在VALUES之前删除分号。