mysqli_select_db()正好需要2个参数

Getting the errors:

Warning: mysqli_select_db() expects exactly 2 parameters, 1 given in C:\Usersoot\Desktop\WebServer\htdocs\test.php on line 9

Warning: mysqli_query() expects at least 2 parameters, 1 given in C:\Usersoot\Desktop\WebServer\htdocs\test.php on line 13

Warning: mysqli_fetch_assoc() expects parameter 1 to be mysqli_result, null given in C:\Usersoot\Desktop\WebServer\htdocs\test.php on line 39

I can't notice the problem, kind of new to this, can anyone see the problem?

Any help is very appreciated!

<?php


//make connection
mysqli_connect('localhost', 'root', '');


//select db
mysqli_select_db('altislife-dev');

$sql="SELECT * FROM players";

$records=mysqli_query($sql);

?>

<html>

    <head>

        <title>Data</title>

    </head>

    <body>

        <table width="600" border="1" cellpadding="1" cellspacing="1">
        <tr>
        <th>uid</th>
        <th>name</th>
        <th>aliases</th>
        <th>playerid</th>
        <th>cash</th>
        <th>bankacc</th>
        <th>coplevel</th>
        <tr>

        <?php
        while($players=mysqli_fetch_assoc($records)) {

            echo "<tr>";
            echo "<td>".$players['uid']."</td>";
            echo "<td>".$players['name']."</td>";
            echo "<td>".$players['aliases']."</td>";
            echo "<td>".$players['playerid']."</td>";
            echo "<td>".$players['cash']."</td>";
            echo "<td>".$players['bankacc']."</td>";
            echo "<td>".$players['coplevel']."</td>";
            echo "</tr>";
        }

        ?>
        </table>
    </body>
</html>

do the correction as below:

$conn = mysqli_connect('localhost', 'root', '');

the first thing that you have to pass connection variable in the select_db as first parameter. as below.

mysqli_select_db($conn,'altislife-dev');

also you have to pass connection variable in mysqli_query() as first parameter as given below.

$records=mysqli_query($conn,$sql);

Yes - if you are going to use the procedural style, pass the return value from mysqli_connect() as the first parameter to mysqli_select_db().

//make connection
 $connection = mysqli_connect('localhost', 'root', '');
mysqli_select_db($connection,'altislife-dev');

Note: you could also pass the database name as the 4th parameter of the call to mysqli_connect() - that will select the database.

$connection = mysqli_connect('localhost', 'root', '', 'altislife-dev');

Also, pass the connection handle to the call to mysqli_query:

$records=mysqli_query($connection, $sql);

I dont know If I am misunderstanding the problem because it is very simple and clear in the document => http://php.net/manual/en/mysqli.select-db.php

=> http://php.net/manual/en/mysqli.query.php

You must pass link to function while selecting,

bool mysqli_select_db ( mysqli $link , string $dbname )

Code modifications required

$con_link = mysqli_connect('localhost', 'root', '');

mysqli_select_db($con_link, 'altislife-dev');

$sql="SELECT * FROM players";

$records=mysqli_query($con_link, $sql);