新的mysqli_connect猫查找数据库 - new mysqli_connect cat find database

new mysqli_connect cat find database

<?php
    $host = "localhost";
    $username = "root";
    $password = "";
    $db = "mineforums";
    $connect = mysqli_connect($host, $username, $password, $db) or die(mysqli_error($connect));
?>

这是我连接到我的数据库的php代码。每当我尝试只是连接时，尽管它什么也没做。我设置登录表单的方式是操作将对此代码，然后不执行任何操作，当我返回索引时，它说未选择数据库，因为如果您登录，它会说"欢迎，{用户名}">

你可以拆分进程

<?PHP
    $host = "localhost";
    $username = "root";
    $password = "";
    $db = "mineforums";
    $connect = mysql_connect($host, $username, $password)OR DIE("Could Not Connect To Server". MySQL_Error());
    if($connect) {
        mysql_select_db($db)OR DIE("Could Not Select Databse". MySQL_Error();
    }
?>