[Question] Using usual MySQL/MySQLi commands

I can use usual MySQL or MySQLi commands in plugins? Example:

PHP:

public function onEnable(){
$link = mysqli_connect("localhost", "root", "********", "database");
$var = mysqli_query($link, "SELECT * FROM `".$this->getConfig()->get("mysqltable")."` WHERE `name`='".$event->getPlayer()->getName()."'");
$var = mysqli_fetch_array($var);
$this->getLogger()->info($var['name']);
}

Thank you.

That's correct. You need to close/free $var though.

PHP:

public function onEnable(){
$link = mysqli_connect("localhost", "root", "********", "database");
$var = mysqli_query($link, "SELECT * FROM `".$this->getConfig()->get("mysqltable")."` WHERE `name`='".$event->getPlayer()->getName()."'");
$var = mysqli_fetch_array($var);
$this->getLogger()->info($var['name']);
mysqli_close($link);
}

?

Actually, to boost the server's performance, I recommend you:
- open connection in onEnable()
- every time you fetch data, remember to close the result
- close connection in onDisable()

How to close result?

Not sure, but if you use the object-oriented style, it is $mysqli_result->close()

This var from pocketmine?

Obviously not. Ive been using the non OOP method of mysqli before. I find it messy if you're working on a bigger scale. learn OOP instead. Like this:
$db = new \mysqli(/*mysql_data*/);
$db->query(); //if you want to query something.
$db->query()->fetch_assoc(); //if u want to fetch query results

Btw, heres a little hint(works on few):
mysqli_query() => $db->query()
if you notice, the "_" in the mysqli_query() function, it acts like "->". its not pretty accurate but helps me with this pattern. The best way is to google for mysqli php OOP examples.

PHP.net/mysqli