MySQL database not selected. where did I miss it? - php

Question

After searching through related questions, I still couldn't get this issue resolved. A "registration successful" page is supposed to pop up after a form is submitted but instead, "No database selected" message appears. where did I miss it. here are the codes.
connect.php
<?php
//connect.php
$server = 'localhost';
$username = 'root';
$password = '';
$database = 'esiro';
$connection = mysqli_connect($server, $username, $password, $database);
mysqli_set_charset($connection,"utf8");
?>
signup.php
<?php
//signup.php
include 'connect.php';
include 'header.php';
echo '<h3>Sign up</h3>';
if($_SERVER['REQUEST_METHOD'] != 'POST')
{
/*the form hasn't been posted yet, display it
note that the action="" will cause the form to post to the same page it is on */
echo
'<form role="form" method="post" action="" class="cover_form">
<div class="form-group">
<label class="labelfield" for="username">User Name:</label><br>
<input class="inputfield" type="text" name="user_name" class="form-control"/><br>
<label class="labelfield" for="pwd">Password:</label><br>
<input class="inputfield" type="password" class="form-control" id="pwd" name="user_pass"><br>
<label class="labelfield" for="pwd"> Confirm Password:</label><br>
<input class="inputfield" type="password" name="user_pass_check" class="form-control" id="pwd"><br>
<label class="labelfield" for="email">Email Address:</label><br>
<input class="inputfield"type="email" class="form-control" id="email" name="user_email">
</div><br>
<input type="submit" class="btn btn-default" value="Complete Registration"/><br>
</form>
';
}
else
{
/* so, the form has been posted, we'll process the data in three steps:
1. Check the data
2. Let the user refill the wrong fields (if necessary)
3. Save the data
*/
$errors = array(); /* declare the array for later use */
if(isset($_POST['user_name']))
{
//the user name exists
if(!ctype_alnum($_POST['user_name']))
{
$errors[] = 'The username can only contain letters and digits.';
}
if(strlen($_POST['user_name']) > 30)
{
$errors[] = 'The username cannot be longer than 30 characters.';
}
}
else
{
$errors[] = 'The username field must not be empty.';
}
if(isset($_POST['user_pass']))
{
if($_POST['user_pass'] != $_POST['user_pass_check'])
{
$errors[] = 'The two passwords did not match.';
}
}
else
{
$errors[] = 'The password field cannot be empty.';
}
if(!empty($errors)) /*check for an empty array, if there are errors, they're in this array (note the ! operator)*/
{
echo 'Uh-oh.. a couple of fields are not filled in correctly...';
echo '<ul>';
foreach($errors as $key => $value) /* walk through the array so all the errors get displayed */
{
echo '<li>' . $value . '</li>'; /* this generates a nice error list */
}
echo '</ul>';
}
else
{
//the form has been posted without, so save it
//notice the use of mysql_real_escape_string, keep everything safe!
//also notice the sha1 function which hashes the password
$sql = "INSERT INTO
users(user_name, user_pass, user_email ,user_date, user_level)
VALUES('" . mysql_real_escape_string($_POST['user_name']) . "',
'" . sha1($_POST['user_pass']) . "',
'" . mysql_real_escape_string($_POST['user_email']) . "',
NOW(),
0)";
$result = mysql_query($sql);
if(!$result)
{
//something went wrong, display the error
echo 'Something went wrong while registering. Please try again later.';
echo mysql_error(); //debugging purposes, uncomment when needed
}
else
{
echo 'Successfully registered. You can now sign in and start posting! :-)';
}
}
}
include 'footer.php';
?>

Answer 1

You should Change the script
$result = mysql_query($sql);
Instead of use this
---------------------
$result = mysqli_query($connection,$sql);
And also remove echo mysql_error();
and use this echo mysql_error($connection);
Add this also in instead of mysql_real_escape_string
$sql = "INSERT INTO
users(user_name, user_pass, user_email ,user_date, user_level)
VALUES('" . mysqli_real_escape_string($connection,$_POST['user_name']) . "',
'" . sha1($_POST['user_pass']) . "',
'" . mysqli_real_escape_string($connection,$_POST['user_email']) . "',
NOW(),
0)";