Insert formfields to SQL - Error - php

Question

Hi so I have a form with 10 fields and I am trying to insert them on an SQL databse through posting them on a PHP page. Connection starts fine, but it returns the error below:
Error: INSERT INTO courses (name, teacher, description, class, DAYONE, DAYTWO, DAYTHREE, STD1, STD2, STD3) VALUES (, , , , , , , , , )
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 ' , , , , , , , , )' at line 1
include_once 'connect.php';
// Create connection
$conn = new mysqli(HOST, USER, PASSWORD, DATABASE);
// Check connection
if ($conn->connect_error) {
die("Connection failed: " . $conn->connect_error);
}
$name = $_POST['name'];
$teacher = $_POST['teacher'];
$description = $_POST['description'];
$class = $_POST['class'];
$dayone = $_POST['dayone'];
$daytwo = $_POST['daytwo'];
$daythree = $_POST['daythree'];
$std1 = $_POST['std1'];
$std2 = $_POST['std2'];
$std3 = $_POST['std3'];
$sql = "INSERT INTO courses (name, teacher, description, class, DAYONE, DAYTWO, DAYTHREE, STD1, STD2, STD3) VALUES ($name, $teacher, $description, $class, $dayone, $daytwo, $daythree, $std1, $std2, $std3)";
if ($conn->query($sql) === TRUE) {
echo "New record created successfully";
} else {
echo "Error: " . $sql . "<br>" . $conn->error;
}
$conn->close();
I should also mention that the database table has one more field called ID type int(11) which is AUTO_INCREMENT and I expect it to be automatically filled everytime a new row is inserted. Am I wrong?
EDIT: Added HTML code since it has been asked
<form name="registration_form" method="post" class="clearfix" action="create.php">
<div class="form-group">
<label for="name">NAME</label>
<input type="text" class="form-control" id="name" placeholder="Course Name">
</div>
<div class="form-group">
<label for="teacher">Teacher</label>
<input type="text" class="form-control" id="teacher" placeholder="Teacher's Name">
</div>
<div class="form-group">
<label for="description">Description</label>
<textarea class="form-control" id="description" placeholder="Description"></textarea>
</div>
<div class="form-group">
<label for="class">Class</label>
<input type="text" class="form-control" id="class" placeholder="Class Name">
</div>
<div class="form-group">
<label for="dayone">Day one</label>
<input type="text" class="form-control" id="dayone" placeholder="Day One">
</div>
<div class="form-group">
<label for="daytwo">Day two</label>
<input type="text" class="form-control" id="daytwo" placeholder="Day Two">
</div>
<div class="form-group">
<label for="daythree">Day three</label>
<input type="text" class="form-control" id="daythree" placeholder="Day Three">
</div>
<div class="form-group">
<label for="std1">std1</label>
<input type="text" class="form-control" id="std1" placeholder="std1">
</div>
<div class="form-group">
<label for="std2">std2</label>
<input type="text" class="form-control" id="std2" placeholder="std2">
</div>
<div class="form-group">
<label for="std1">std3</label>
<input type="text" class="form-control" id="std3" placeholder="std3">
</div>
<div class="checkbox">
<label>
<input type="checkbox">I Understand Terms & Conditions
</label>
</div>
<button type="submit" class="btn pull-right">Create Course</button>
</form>

Answer 1

This should help you identify if the issue is POST variables not being received.
Also a little bit more security.
// create an array of all possible input values
$input_array = array('name', 'teacher', 'description', 'class', 'dayone', 'daytwo', 'daythree', 'std1', 'std2', 'std3');
// create an input array to put any received data into for input to the database
$input_array = array();
include_once 'connect.php';
// Create connection
$conn = new mysqli(HOST, USER, PASSWORD, DATABASE);
// Check connection
if ($conn->connect_error) {
die("Connection failed: " . $conn->connect_error);
}
// loop through the possible input values to check that a post variable has been received for each.. if received escape the data ready for input to the database
foreach($input_array as $key => $value)
{
if(!isset($_POST[$value])) {
die("no {$value} post variables received");
}
$input_array[$value] = mysqli_real_escape_string($conn, $_POST[$value]);
}
$sql = "INSERT INTO courses (name, teacher, description, class, DAYONE, DAYTWO, DAYTHREE, STD1, STD2, STD3) VALUES ('{$input_array['name']}', '{$input_array['teacher']}', '{$input_array['description']}', '{$input_array['class']}', '{$input_array['dayone']}', '{$input_array['daytwo']}', '{$input_array['daythree']}', '{$input_array['std1']}', '{$input_array['std2']}', '{$input_array['std3']}')";
if ($conn->query($sql) === TRUE) {
echo "New record created successfully";
} else {
echo "Error: " . $sql . "<br>" . $conn->error;
}
$conn->close();

Answer 2

Try:
$sql = "INSERT INTO courses (name, teacher, description, class, DAYONE, DAYTWO, DAYTHREE, STD1, STD2, STD3) VALUES ('".$name."', '".$teacher."', '".$description."', '".$class."', '".$dayone."', '".$daytwo."', '".$daythree."', '".$std1."', '".$std2."', '".$std3."')";
Also, use:
$name = $conn->real_escape_string($_POST['name']);
//etc
Also add name to your form fields:
<input name="class" type="text" class="form-control" id="class" placeholder="Class Name">