PHP prepared statement not working [duplicate] - php

Question

This question already has answers here:
How do I escape reserved words used as column names? MySQL/Create Table
(4 answers)
Closed 2 years ago.
I am making a prepared statement in PHP and my code is fine until I add in 'id' and 'key' to my parameters. They are definitely in the table that I am requesting too. What is wrong? Thanks in advance!
ERROR: Call to a member function bind_param() on boolean
if($_POST['userx']){
echo '<div id="div2"><div id="font2">Dashboard</div>';
$queryA = "SELECT name,profo,password,id,key FROM collegestudents WHERE email = ?";
$stmt = $connection->prepare($queryA);
$stmt->bind_param('s',$_POST['userx']);
$stmt->bind_result($name1,$profo,$password1,$key,$id);
$stmt->execute();
$stmt->fetch();
$stmt->close();

Answer 1

Key is a reserved keyword in mysql.
It's a good habit to enclose field names and table names in backticks in queries but also to check for errors.
$queryA = "SELECT `name`,`profo`,`password`,`id`,`key` FROM `collegestudents` WHERE `email` = ?";
$stmt = $connection->prepare($queryA);
if ($stmt) {
$stmt->bind_param('s',$_POST['userx']);
...
}
else {
echo "MySQL ERROR: " . $connection->error;
}

Answer 2

$stmt = $connection->prepare($queryA);
returns boolean(false)
make sure your query is correct
you can do a simple check like this
$stmt = $connection->prepare($queryA);
if (!$stmt) {
echo "failed to run";
} else {
$stmt->bind_param('s',$_POST['userx']);
$stmt->bind_result($name1,$profo,$password1,$key,$id);
$stmt->execute();
$stmt->fetch();
}
Edit:
if you are using PDO you were doing it wrong it should be like this
$stmt = $conn->prepare("SELECT name,profo,password,id,key FROM
collegestudents WHERE email = :email");
$stmt->bindParam(':email', $email);

Answer 3

Change your database connection file with
<?php $con = new PDO('mysql:host=127.0.0.1;dbname=yourdatabasename;','username',''); ?>
Then change below line
$queryA = "SELECT name,profo,password,id,key FROM collegestudents WHERE email = ?";
$stmt = $connection->prepare($queryA);
$stmt->bind_param('s',$_POST['userx']);
$stmt->bind_result($name1,$profo,$password1,$key,$id);
$stmt->execute();
with
$queryA = "SELECT name,profo,password,id,key FROM collegestudents WHERE email = :v";
$stmt = $connection->prepare($queryA);
$stmt->execute( array('v' => $_POST['userx']) );