MySQLI DB预计Param为1

Question

我最近一直致力于我自己的PHP项目，当我将文件传输到WAMP时，我一直遇到这个错误。

这是我得到的错误：

  

（！）警告：mysqli_select_db（）要求参数1为mysqli，第4行的C：\ wamp64 \ www \ link.php中给出的字符串

这是我的代码：

    <?php
    @include_once 'settings.php';
    //session_start
    $link = mysqli_connect($servername, $username, $password); //MySQL Host, Username, password
    $db_selected = mysqli_select_db('database', $link); //MySql database
    mysqli_query("SET NAMES utf8");

    function fetchinfo($rowname, $tablename, $finder, $findervalue)
    {
        if ($finder == "1")
            $result = mysqli_query("SELECT $rowname FROM $tablename");
        else
            $result = mysqli_query("SELECT $rowname FROM $tablename WHERE `$finder` =`$findervalue`");
        $row = mysqli_fetch_assoc($result);
        return $row[$rowname];
    }

    function secureoutput($string)
    {
        $string = mysqli_real_escape_string($string);
        $string = htmlentities(strip_tags($string));
        $string = str_replace('>', '', $string);
        $string = str_replace('<', '', $string);
        $string = htmlspecialchars($string);
        return $string;
   }


   ?>