PHP: $variable is causing the php code to break/exit(?) - php

Question

I am coding my first php app and I am basing it off a tutorial I was working on that worked. My code as of right now works fine until I get to the $var = $connection->query("INSERT INTO . . . etc.
At this point, the code immediately after the first $ just shows up as plaintext in firefox. (google shows the whole thing as text blah).
I will post my code here:
<?php
$dbServername = "localhost";
$dbUsername = "root";
$dbPassword = "";
$dbName = "cowboyserver";
$conn = mysqli_connect($dbServername, $dbUsername, $dbPassword);
mysqli_select_db($dbName, $conn);
$email = ($_POST['email']);
if(!$conn){
echo 'error';
}else{
$query = $conn->query("INSERT INTO email_list (email) VALUES ('$email')");
}
mysqli_query($query);
header("Location: ../index.html?signup=success");
echo '<p>email entered !! ! ! ! ! ! !! !! ! ! ! ! !</p>' ;
Additionally, here is the HTML : : : :
<form autocomplete="on" action="includes/signup.inc.php" method="POST">
<input type="email" name="email" placeholder="put your email here" class="blah"/>
</form>
EDIT:
After trying some solutions, I have found that my php code breaks at a seemingly random point in the code. In the second answer posted, for example, the php code runs until it gets to "$conn->connect_error" in the if statement and then prints out everything after the -> instead of executing it.

Answer 1

Changes you needed:-
1.Need to change file name from signup.inc.php to signup.php and then use it in from like below:-
<form autocomplete="on" action="includes/signup.php" method="POST">
<input type="email" name="email" placeholder="put your email here" class="blah"/>
</form>
2.change in signup.php(the file you renamed) code (changes are commented):-
<?php
//comment these two lines when code executed successfully
error_reporting(E_ALL);
ini_set('display_errors',1);
if(!empty($_POST['email']){ // check posted data coming or not
$dbServername = "localhost";
$dbUsername = "root";
$dbPassword = "";
$dbName = "cowboyserver";
$conn = mysqli_connect($dbServername, $dbUsername, $dbPassword,$dbName); //add dbname here itself
//check conneced or not
if(!$conn){ // $ missed
die('connection problem'.mysqli_connect_error());//check for real connection problem
}else{
$email = $_POST['email'];// remove ()
//don't mix oop way to procedural way and use prepared statements
$stmt = mysqli_prepare($conn, "INSERT INTO email_list (email) VALUES (?)"));
/* bind parameters for markers */
mysqli_stmt_bind_param($stmt, "s", $email);
/* execute query */
if(mysqli_stmt_execute($stmt)){//check query executes or not
header("Location: ../index.html?signup=success");
echo '<p>email entered !! ! ! ! ! ! !! !! ! ! ! ! !</p>';
exit();
}else{
echo "insersion failde because of".mysqli_error($conn);
}
}
}else{
echo "please fill the form";
}
Note:- always use prepared statements to prevent from SQL INJECTION.Thanks

Answer 2

Try this. Change your form to include a submit button. Then only you can access values using $_POST.
<form autocomplete="on" action="includes/signup.php" method="POST">
<input type="email" name="email" placeholder="put your email here" class="blah"/>
<input type="submit" value="Form Submission" name="submitBtn">
</form>
Your signup.php page:
<?php
$dbServername = "localhost";
$dbUsername = "root";
$dbPassword = "";
$dbName = "cowboyserver";
// Create connection
$conn = new mysqli($conn = new mysqli($dbServername, $dbUsername, $dbPassword, $dbName));
// Check connection
if ($conn->connect_error) {
die("Connection failed: " . $conn->connect_error);
}
if(isset($_POST['submitBtn'])) { //form submission occured
$email = $_POST['email'];
$sql = "INSERT INTO email_list (email) VALUES ('$email')";
if ($conn->query($sql)) {
echo '<p>email entered !! ! ! ! ! ! !! !! ! ! ! ! !</p>';
header("Location: ../index.html?signup=success");
exit();
} else {
echo "Error: " . $sql . "<br>" . $conn->error;
}
} else {
echo "Form Submission Error";
}
$conn->close();
?>
Hope it's helpful.