How to make mysqli connect function? - php

Question

I'm having a problem with a function that connects me to the database using mysqli. What I'm aiming to have is to just type getConnected(); where I need the connection.
This is the code:
function getConnected()
{
$host = 'localhost';
$user = 'logintest';
$pass = 'logintest';
$db = 'vibo';
$mysqli = new mysqli($host, $user, $pass, $db);
if ($mysqli->connect_error) {
die('Connect Error (' . mysqli_connect_errno() . ') '
. mysqli_connect_error());
}
}
This is the error I get when I try to use $mysqli after calling getConnected():
Notice: Undefined variable: mysqli in C:\xampp\htdocs\xampp\loginsystem\index.php on line 19

Answer 1

As some users have suggested (and is the best way), return the mysqli instance
function getConnected($host,$user,$pass,$db) {
$mysqli = new mysqli($host, $user, $pass, $db);
if($mysqli->connect_error)
die('Connect Error (' . mysqli_connect_errno() . ') '. mysqli_connect_error());
return $mysqli;
}
Example:
$mysqli = getConnected('localhost','user','password','database');

Answer 2

You don't need to create such function. The connection to mysqli is only 3 lines of code when done properly. Definition and execution of such function would add twice as much.
Remember to always follow the three steps when opening a connection:
Enable mysqli error reporting.
Create instance of mysqli class.
Set the proper charset. Recommended one is utf8mb4
If you would like to have these 3 lines wrapped in a function you could do something like this:
function getConnected(): \mysqli {
$host = 'localhost';
$user = 'logintest';
$pass = 'logintest';
$db = 'vibo';
mysqli_report(MYSQLI_REPORT_ERROR | MYSQLI_REPORT_STRICT);
$mysqli = new mysqli($host, $user, $pass, $db);
$mysqli->set_charset('utf8mb4');
// return the instance of mysqli class
return $mysqli;
}
However, hardcoding the values does not make much sense. The values should be coming either from environment variables (e.g. read using getenv() function) or from config file. For example:
function getConnected(): \mysqli {
mysqli_report(MYSQLI_REPORT_ERROR | MYSQLI_REPORT_STRICT);
$mysqli = new mysqli(getenv('DB_HOST'), getenv('DB_USER'), getenv('DB_PASS'), getenv('DB_NAME'));
$mysqli->set_charset('utf8mb4');
// return the instance of mysqli class
return $mysqli;
}