mysqli_select_db() expects parameter 1 to be mysqli on line 8

问题

I Don't know what actually I should do and if there is something wrong somebody please correct it and give it thanks in advance

<?php
    $db_host = 'localhost';
    $db_user = 'root';
    $db_pass = '';
    $db_name = 'cms';

    $conn = mysqli_connect($db_host,$db_user,$db_pass) or die(mysql_error());
        mysqli_select_db($db_name,$conn);

?>

回答1:

Use this:

$con = mysqli_connect($hostname,$user,$password,$database);

You don't need:

mysqli_select_db

Your code will be:

$db_host = 'localhost';
$db_user = 'root';
$db_pass = '';
$db_name = 'cms';

$con = mysqli_connect($db_host,$db_user,$db_pass,$db_name);

回答2:

Why you trying use longest way? Instead, try:

$con=mysqli_connect('localhost', 'root', '', 'cms');

回答3:

Try this:

 mysqli_select_db($conn, $db_name);

来源：https://stackoverflow.com/questions/21498356/mysqli-select-db-expects-parameter-1-to-be-mysqli-on-line-8