Access denied for user ''#'localhost' (using password: NO) [duplicate] - php

Question

This question already has answers here:
Can I mix MySQL APIs in PHP?
(4 answers)
Closed 4 years ago.
Attempting to connect to localhost sql db using the following code (Not doing anything with query at this point just want the query to execute):
<?php
$host = "localhost";
$port = 3306;
$socket = "";
$user = "root";
$password = "Password1";
$dbname = "CIIP_WIKI";
$con = new mysqli($host, $user, $password, $dbname, $port);
if(!$con)
{
echo ("db connection failed!");
die ('Could not connect to the database server' . mysqli_connect_error());
}
else {
echo ("db connection established.");
echo ("<br/>");
}
$query = sprintf("SELECT first_name FROM actor WHERE actor_id='1'");
$result = mysql_query($query);
$con->close();
?>
I keep getting the following...
Welcome
db connection established.
Warning: mysql_query(): Access denied for user ''#'localhost' (using password: NO) in C:\Program Files (x86)\EasyPHP-12.1\www\Cisco Wiki\index.php on line 31
Warning: mysql_query(): A link to the server could not be established in C:\Program Files (x86)\EasyPHP-12.1\www\Cisco Wiki\index.php on line 31
Why does this not work?

Answer 1

This is because you create a connection using mysqli_ and then use mysql_ to try to fetch your result. They are different API's.
<?php
/* You should enable error reporting for mysqli before attempting to make a connection */
mysqli_report(MYSQLI_REPORT_ERROR | MYSQLI_REPORT_STRICT);
$mysqli = mysqli_connect('localhost', 'my_user', 'my_password', 'my_db');
/* Set the desired charset after establishing a connection */
mysqli_set_charset($mysqli, 'utf8mb4');
printf("Success... %s\n", mysqli_get_host_info($mysqli));
Example taken from the PHP manual

Answer 2

This warning will be logged anytime you try to execute a query without a valid connection object being available.
In your case you thought you had a valid connection object available, but you created it using mysqli while your query is being executed using mysql. Those are two different APIs and so the mysql_query function was looking for a mysql connection object and didn't find it.