How to rectify this error => Warning: mysql_fetch_assoc() expects parameter 1 to be resource

Question

<?php

    function get_msg() {

        $query = "SELECT `Sender`, `Message` FROM `chat`.`chat` ORDER BY `Msg_ID` DESC";

        $run = mysql_query($query);

        $messages = array();

        while($message = mysql_fetch_assoc($run)) {
            $messages[] = array('sender'=>$message['Sender'],
                                'message'=>$message['Message']);
        }

        return $messages;

    }

    function send_msg($sender, $message) {

        if(!empty($sender) && !empty($message)) {

            $sender     = mysql_real_escape_string($sender);
            $message    = mysql_real_escape_string($message);

            $query = "INSERT INTO `chat`.`chat` VALUES (null, '{$sender}', '$message')";

            if($run = mysql_query($query)) {
                return true;
            } else {
                return false;
            }

        } else {
            return false;
        }
    }

?>

Answer 1

Try this:

Such error only occurs when your query failed to fetch data.

>> Try to echo your query and run in mysql or database you used.
>> Check if it fetches data.
>> If it fetches then check your syntax of all lines in php code.

-- Thanks

Answer 2

The error message you get means that your query has problems - errors.
Always, always use the mysql_error() function during development.
For example:

$result = mysql_query($query) or die(mysql_error());

This will contain everything you need to fix your query.

Side note: stop using mysql_ functions and switch to mysqli_ or PDO.