PHP mysql error when running INSERT [duplicate] - php

Question

This question already has answers here:
When to use single quotes, double quotes, and backticks in MySQL
(13 answers)
Closed 8 years ago.
Can someone help me understand this error?
Fatal error: Call to a member function bind_param() on a non-object in C:\MAMP\htdocs\MyCMS\insert_posttwo.php on line 64
<?php
$mysqli = mysqli_connect("localhost", "root", "root", "mycms");
if (isset($_POST['submit'] )) {
$post_author = $_POST['post_author'];
$stmt = $mysqli->prepare ("INSERT INTO 'posts' ('post_author') VALUES(?)");
$stmt->bind_param('s', $post_auth);
$post_auth = $post_author;
$stmt->execute();
echo "<script>alert('Post has been published')</script>";
echo "<script>window.open('insert_post','_self')</script>";
$stmt->close();
}
?>

Answer 1

Instead of single quotes ' use backticks ` to escape field or table names .
$stmt = $mysqli->prepare ("INSERT INTO `posts` (`post_author`) VALUES(?)");

Answer 2

Change this (For columns you have to use back ticks not single quotes):
'posts'
to:
`posts`
Also you have to create a object and not the procedural method otherwise you can't do that so use this:
$mysqli = new mysqli_connect("localhost", "root", "root", "mycms");
//^^^ See here so you create a object
And also you have to close your connection like this:
$mysqli->close();
//^^^^^ Close the connection and not the stmt