Mysqli_select_db() expects parameter 1 to be mysqli, string given in /storage/ssd3/011/325011/public_HTML/vote/app/login.php on line 18 unable to select database

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PHP

<?php
//Start session
session_start();

//Array to store validation errors
$errmsg_arr = array();

//Validation error flag
$errflag = false;

//Connect to mysqli server
$link = mysqli_connect('localhost','id325011_admin',"dddddd");
if(!$link) {
die('Failed to connect to server: ' . mysqli_error());
}

//Select database
$db_select = mysqli_select_db($link->conn, id325011_onlinevoting );
$db = mysqli_select_db('id325011_onlinevoting', $link);
if(!$db) {
die("Unable to select database");
}

//Function to sanitize values received from the form. Prevents SQL injection
function clean($str) {
$str = @trim($str);
if(get_magic_quotes_gpc()) {
$str = stripslashes($str);
}
return mysqli_real_escape_string($str);
}

//Sanitize the POST values
$login = clean($_POST['username']);
$password = clean($_POST['password']);
$position = clean($_POST['asas']);
$stat='notvoted';

//Input Validations
if($login == '') {
$errmsg_arr[] = 'Username missing';
$errflag = true;
}
if($password == '') {
$errmsg_arr[] = 'Password missing';
$errflag = true;
}

//If there are input validations, redirect back to the login form
if($errflag) {
$_SESSION['ERRMSG_ARR'] = $errmsg_arr;
session_write_close();
header("location: index.php");
exit();
}

//Create query
if($position=='Admin') {
$qry="SELECT * FROM admin WHERE username='$login' AND password='$password'";
}
if($position=='Student') {
$qry="SELECT * FROM students WHERE username='$login' AND password='$password' AND status='$stat'";
}
$result=mysqli_query($qry);

//Check whether the query was successful or not
if($result) {
if(mysqli_num_rows($result) > 0) {
//Login Successful
if($position=='Student') {
session_regenerate_id();
$member = mysqli_fetch_assoc($result);
$_SESSION['SESS_MEMBER_ID'] = $member['username'];
$_SESSION['SESS_COURSE'] = $member['course'];
$_SESSION['NAME'] = $member['name'];
session_write_close();
header("location: candidates_list.php");
exit();
}
if($position=='Admin') {
session_regenerate_id();
$member = mysqli_fetch_assoc($result);
$_SESSION['SESS_MEMBER_ID'] = $member['id'];
session_write_close();
header("location: admin/index.php");
exit();
}
}else {
//Login failed
header("location: index.php");
exit();
}
}else {
die("Query failed");
}
?>

What I have tried:

$db = mysqli_select_db('id325011_onlinevoting', $link);