prepared statement not inserting data into database - php

Question

My prepared statements for inserting data into a database are not working. I have had these issues accross the board but I am including one example just incase I am making a simple mistake. The query is running ok as I am getting a message which I placed myself within the code, however nothing is being entered into the actual database. MY issues so far with prepared statements is the lack of feedback you get when something isnt working. Any help would be greatly appreciated.
<?php
if(isset($_POST['newsubject'])){
include('../connection/conn.php');
//Prepare the insert statement
$insertquery = "INSERT INTO miiLearning_Tutors(tutor_id,subject_level,
price, subjects) VALUES (?,?,?,?)";
if($stmt = mysqli_prepare($conn, $insertquery)){
//bind variable to the prepared statement as parameters
mysqli_stmt_bind_param($stmt, "iidi", $newtutor, $newsubject,
$newlevel, $newprice);
//Set Values
$newtutor = $_POST["tutorId"];
$newsubject = $_POST["subjects"];
$newlevel = $_POST["subjectlevel"];
$newprice = $_POST["price"];
mysqli_stmt_execute($stmt);
echo"<p>Query Ran</p>";
} else{
echo "ERROR: Could not prepare query: $query . " .mysqli_error($conn);
}
}
?>
HTML for form:
<form enctype="multipart/form-data" action='updatesubjects.php' method="post" id="update-subjects-form" name="new-subject" >
<fieldset>
<!--Tutor ID (Posted from previous page) -->
<input type="hidden" name="tutorId" value='<?php echo "$userarray[0]";?>'>
<!-- Subject -->
<div class="form-group">
<label for="subjects">Subject</label>
<select name="subjects" type="text" class="form-control">
<?php
if(mysqli_num_rows($subjectsresult)>0){
while($row = mysqli_fetch_assoc($subjectsresult)){
$get_subjectid = $row['subject_id'];
$get_subjectname = $row['subject'];
echo "<option value='$get_subjectid'>$get_subjectname</option>";
}
}
?>
</select>
</div>
<!-- Level -->
<div class="form-group">
<label for="subjectlevel">Subject Level</label>
<select name="subjectlevel" type="text" class="form-control">
<?php
if(mysqli_num_rows($levelresult) > 0){
while($row = mysqli_fetch_assoc($levelresult)){
$get_levelid = $row['level_id'];
$get_namelevel = $row['level'];
echo "<option value='$get_levelid'>$get_namelevel</option>";
}
}
?>
</select>
</div>
<div class="form-group">
<label for="subjectlevel">Price</label>
<input type='number' step='0.01' min='0' name='price'>
</div>
<button class="btn btn-primary" type="submit" name="newsubject" id="bookingsform">Submit form</button>
</fieldset>
</form>
I apologies for any poor indentation

Answer 1

You need to declare your variables and assign value to them before binding. At the moment you should have undefined variables.
On development environment ensure error reporting is on.
<?php
error_reporting(-1);
ini_set('display_errors', 1);
if(isset($_POST['newsubject'])){
include('../connection/conn.php');
//Set Values
$newtutor = $_POST["tutorId"];
$newsubject = $_POST["subjects"];
$newlevel = $_POST["subjectlevel"];
$newprice = $_POST["price"];
//Prepare the insert statement
$insertquery = "INSERT INTO miiLearning_Tutors(tutor_id,subject_level, price, subjects) VALUES (?,?,?,?)";
if($stmt = mysqli_prepare($conn, $insertquery)){
//bind variable to the prepared statement as parameters
mysqli_stmt_bind_param($stmt, "iidi", $newtutor, $newsubject, $newlevel, $newprice);
mysqli_stmt_execute($stmt);
echo"<p>Query Ran</p>";
} else{
echo "ERROR: Could not prepare query: $query . " .mysqli_error($conn);
}
}
?>