Call to a member function execute() on a non-object in - php

Question

I have the following error, and this is the exact same form processing file I use for registering a user, but I changed it for the appropriate table and columns. While the reg works fine every time.
Here is the code where the error is located:
$sql = "INSERT INTO events1 (eventname,about,website) VALUES (:yas,:yasas,:yasasha)";
$q = $conn->prepare($sql);
$q->execute(array(':yas'=>$eventname,':yasas'=>$about,':yasasha'=>$website));
Here is the full code:
<?php
$servername = "localhost";
$username = "root";
$password = "Af2vaz93j68";
$dbname = "pdo_ret";
// Create connection
$conn = new mysqli($servername, $username, $password, $dbname);
// Check connection
if ($conn->connect_error) {
die("Connection failed: " . $conn->connect_error);
}
$eventname = $_POST['eventname'];
$about = $_POST['about'];
$website = $_POST['website'];
if($eventname == '') {
$errmsg_arr[] = 'You must enter your Email';
$errflag = true;
}
if($about == '') {
$errmsg_arr[] = 'You must enter your Password';
$errflag = true;
}
if($website == '') {
$errmsg_arr[] = 'You must enter First Name';
$errflag = true;
}
$sql = "INSERT INTO events1 (eventname,about,website) VALUES (:yas,:yasas,:yasasha)";
$q = $conn->prepare($sql);
$q->execute(array(':yas'=>$eventname,':yasas'=>$about,':yasasha'=>$website));
if ($conn->query($sql) === TRUE) {
echo "New record created successfully";
} else {
echo "Error: " . $sql . "<br>" . $conn->error;
}
$conn->close();
?>

Answer 1

Youre confusing PDO and mysqli. mysqli does not support named parameters so you stmt is not compiling and Mysqli::prepare is returning false. Additionally mysqli does not support passing the param to be bound through mysqli_stmt::execute so even if you switch to positional placeholders your execute will fail.
This is what you would need for mysqli:
$sql = "INSERT INTO events1 (eventname,about,website) VALUES (?,?,?)";
$stmt = $conn->prepare($sql);
// check to make sure the statement was prepared without error
if ($stmt) {
// the statement is good - proceed
$stmt->bind_param('sss', $eventname, $about, $website);
$stmt->execute();
}
Additionally this makes no sense at all:
if ($conn->query($sql) === TRUE) {
echo "New record created successfully";
} else {
echo "Error: " . $sql . "<br>" . $conn->error;
}
This will just run the same query again either inserting a second row of the exact same data, or perhaps creating a duplicate key error depending upon your schema.
If you want to test that the previous query succeeded you would do something like:
$sql = "INSERT INTO events1 (eventname,about,website) VALUES (?,?,?)";
$stmt = $conn->prepare($sql);
if ($stmt) {
$stmt->bind_param('sss', $eventname, $about, $website);
$success = $stmt->execute();
} else {
$success = false;
}
if ($success === true) {
echo "New record created successfully";
} else {
echo "Error: " . $sql . "<br>" . $conn->error;
}
If you want to use PDO (which i prefer and usually recommend) your code would look something like this:
$conn = PDO("mysql:host=$dbhost;dbname=$dbname", $dbuser, $dbpass);
$conn->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
try {
$sql = "INSERT INTO events1 (eventname,about,website) VALUES (:yas,:yasas,:yasasha)";
$stmt = $conn->prepare($sql);
$stmt->execute(array(':yas'=>$eventname,':yasas'=>$about,':yasasha'=>$website));
echo "New record created successfully";
} catch (PDOException $e) {
echo "Error: " . $sql . "<br>" . $e->getMessage();
}