bind_param doesn't replace ?s in my prepared statement - php

Question

It registers the user successfully. But when I check it on my database, all of the values are 0s. What's the problem?
here's the function code:
public function insertUser($email, $firstName, $lastName, $encryptedPassword, $salt)
{
//SQL language - command to insert data
$sql = "INSERT INTO users (email, firstName, lastName, password, salt) VALUES (email=?, firstName=?, lastName=?, password=?, salt=?)";
//preparing SQL for execution by checking the validity
$statement = $this->conn->prepare($sql);
//if error
if (!$statement)
{
throw new Exception(($statement->error));
}
//assigning variables instead of '?', after checking the preparation and validity of the SQL command
$statement->bind_param('sssss', $email, $firstName, $lastName, $encryptedPassword, $salt);
//result will store the status/result of the execution of SQL command
$result = $statement->execute();
return $result;
}
The parameters for the function get set with the correct values when called, I tested it
I'm pretty new to PHP. If i correct my function, it doesn't create a new user. It doesn't even print out anything in the browser window. Here's the piece of code that calls this one (maybe it helps you with finding the solution):
$result = $access->insertUser($email, $firstName, $lastName, $encryptedPassword, $salt);
//result is positive
if ($result)
{
//throw back the user details
$return['status'] = '200';
$return['message'] = 'Successfully registered';
$return['email'] = $email;
$return['firstName'] = $firstName;
$return['lastName'] = $lastName;
echo json_encode($return);
$access->disconnect();
}

Answer 1

Your query is wrong.
//columns are declared here
$sql = "INSERT INTO users (email, firstName, lastName, password, salt) VALUES (email=?, firstName=?, lastName=?, password=?, salt=?)";
//you do not need to declare your columns again
Simple change your query to
$sql = "INSERT INTO users (email, firstName, lastName, password, salt) VALUES (?, ?, ?, ?, ?)";
Also, it appears as though you are storing your password and the salt separately, that tells me you are rolling your own hashing algorithm, there isn't really a need for this. I would remove your salt column, and use password_hash() for your password column.

Answer 2

remove the column=?
$sql = "INSERT INTO users (email, firstName, lastName, password, salt) VALUES (?, ?, ?, ?, ?)";
the code
column=?
in your value assignment is evalued as boolean condition that return false (0)