database is not getting connected

Question

I am not able to connect to my database. Here's my code could you please help me out.

<?php

error_reporting(E_ALL); 
ini_set('display_errors', 1);

define('DB_HOST', 'mysql.hostinger.in');
define('DB_NAME', 'u25*****41_hari');
define('DB_USERNAME', 'u25*****41_hari');
define('DB_PASSWORD', 'hariharan');

$link = mysqli_connect(DB_HOST, DB_USERNAME,    DB_PASSWORD);

if (!$link) {
     die('Could not connect line 9');
}

$DB_SELECT = mysqli_select_db(DB_NAME, $link);

if (!$DB_SELECT) {
        die('Could not connect line 15');
}

$valueone = $_POST['Name'];
$valuetwo = $_POST['Username'];
$valuethree = $_POST['Password'];
$valuefour = $_POST['Mobile_Number'];

$sqlone = "INSERT INTO Account (Name) VALUES ('$valueone')";
$sqltwo = "INSERT INTO Account (Username) VALUES ('$valuetwo')";
$sqlthree = "INSERT INTO Account (Password) VALUES ('$valuethree')";
$sqlfour = "INSERT INTO Account (Mobile_Number) VALUES ('$valuefour')";

if (!mysql_query($sqlone) || !mysql_query($sqltwo) || !mysql_query($sqlthree) || !mysql_query($sqlfour) || !mysql_query($sqlfive)) {
     die('Could not connect name line 33');
}


mysql_close();
?>

This is the error I get:

Warning: mysqli_select_db() expects parameter 1 to be mysqli, string given in /home/u256114841/public_html/login.php on line 17 Could not connect line 15

Answer 1

Foreword: Make sure that all your form element name attributes match the POST arrays and that your database uses the correct types for the data input and their lengths.

---

In mysqli, the connection comes first.

you have

$DB_SELECT = mysqli_select_db(DB_NAME, $link);

which should read as

$DB_SELECT = mysqli_select_db($link, DB_NAME);

Read the manual:

• http://php.net/manual/en/mysqli.select-db.php

But... you would be better off using all 4 parameters all in one go:

$link = mysqli_connect(DB_HOST, DB_USERNAME, DB_PASSWORD, DB_NAME);

while getting rid of $DB_SELECT = mysqli_select_db($link, DB_NAME);

• Reference: http://php.net/manual/en/function.mysqli-connect.php

However, you are mixing MySQL APIs with mysql_ functions.

Those different APIs do not intermix.

Consult the following on Stack:

• Can I mix MySQL APIs in PHP?

You also did not post your HTML form to go with your POST arrays.

Make sure that your form does use a POST method and that your inputs all hold the same name attribute.

NB: $_POST['Name'] with name="name" will fail, if that is what your form element is named as and the same for all the other inputs. Those are case-sensitive.

Add error reporting to the top of your file(s) which will help find errors.

<?php 
error_reporting(E_ALL);
ini_set('display_errors', 1);
mysqli_report(MYSQLI_REPORT_ERROR | MYSQLI_REPORT_STRICT);

// rest of your code

Sidenote: Displaying errors should only be done in staging, and never production.

Additionally, your code is prone to an SQL injection. Use a prepared statement.

• https://en.wikipedia.org/wiki/Prepared_statement

You don't need to use seperate queries like that.

Just add the columns and values all in one go.

$sqlone = "INSERT INTO Account (Name, Username, Password, Mobile_Number) 
            VALUES ('$valueone', '$valuetwo', '$valuethree', '$valuefour')";

Using mysqli_real_escape_string() for all your values.

Ie:

$valueone = mysqli_real_escape_string($link, $_POST['Name']);

and doing the same for the others.

I also noticed that you may be storing passwords in plain text. This is not recommended.

Use one of the following:

• CRYPT_BLOWFISH
• crypt()
• bcrypt()
• scrypt()
• On OPENWALL
• PBKDF2
• PBKDF2 on PHP.net
• PHP 5.5's password_hash() function.
• Compatibility pack (if PHP < 5.5) https://github.com/ircmaxell/password_compat/

Other links:

• PBKDF2 For PHP

---

Additional references:

• http://php.net/manual/en/mysqli.error.php
• http://php.net/manual/en/mysqli.real-escape-string.php
• https://en.wikipedia.org/wiki/SQL_injection
• How can I prevent SQL injection in PHP?

Answer 2

The correct is

mysqli_select_db ( mysqli $link , string $dbname )

You are putting

mysqli_select_db ( string $dbname , mysqli $link )

Fix this and tell me if worked. For more info, see docs: http://php.net/manual/pt_BR/mysqli.select-db.php