How do I connect my website to a MySQL database? - php

Question

Below is the code I have in my Sublime, but the database isn't being called.
<?php$username="root";
$password="changedpassword";$database="User";
$field1-name=$_POST['name'];
$field2-name=$_POST['password'];
$field3-name=$_POST['email'];
$field4-name=$_POST['sex'];
$field5-name=$_POST['school'];
$field6-name=$_POST['birth'];
mysql_connect(localhost,$username,$password);
#mysql_select_db($database) or die( "Unable to select database");
$query = "INSERT INTO create_user (name, password, email, sex, school, birth) VALUES('','$field1-name','$field2-name',
'$field3-name','$field4-name','$field5-name','$field6-name')";mysql_query($query);mysql_close();?>

Answer 1

Let's go through this step by step. First, here's your current code, tidied up to be readable:
<?php
$username = "root";
$password = "changedpassword";
$database = "User";
$field1_name = $_POST['name'];
$field2_name = $_POST['password'];
$field3_name = $_POST['email'];
$field4_name = $_POST['sex'];
$field5_name = $_POST['school'];
$field6_name = $_POST['birth'];
mysql_connect(localhost, $username, $password);
#mysql_select_db($database) or die("Unable to select database");
$query = "
INSERT INTO
create_user
(
name,
password,
email,
sex,
school,
birth
)
VALUES
(
'',
'$field1_name',
'$field2_name',
'$field3_name',
'$field4_name',
'$field5_name',
'$field6_name'
)
";
mysql_query($query);
mysql_close();
?>
I've made only two changes (tidied the whitespace, and used _name instead of -name, as PHP variables cannot contain hyphens), but it's already a big improvement. The code is no longer an eyesore. It does not have syntax errors, and it is readable. There are still, though, a large number of problems.
First, you see that we are inserting seven values into six columns. This will be a problem. Fix that by removing the first blank value:
$query = "
INSERT INTO
create_user
(
name,
password,
email,
sex,
school,
birth
)
VALUES
(
'$field1_name',
'$field2_name',
'$field3_name',
'$field4_name',
'$field5_name',
'$field6_name'
)
";
Now we have something that might actually work. It's painfully insecure, with massive potential for SQL injection attacks, and it won't work on the latest PHP because the mysql_ functions have been removed, but it might actually kind of work somewhere. You wouldn't want to put it into production, but for test purposes, we're getting somewhere.

Answer 2

MySQL is deprecated since PHP 5.6 and is insecure, use PDO or MySQLi instead.
Connecting with MySQLi
<?php
//MySQLi information
$db_host = "localhost";
$db_username = "username";
$db_password = "password";
//connect to mysqli database (Host/Username/Password)
$connection = mysqli_connect($db_host, $db_username, $db_password) or die("Error " . mysqli_error());
//select MySQLi dabatase table
$db = mysqli_select_db($connection, "table") or die("Error " . mysqli_error());
$field1_name = $_POST['name'];
$field2_name = $_POST['password'];
$field3_name = $_POST['email'];
$field4_name = $_POST['sex'];
$field5_name = $_POST['school'];
$field6_name = $_POST['birth'];
$query = mysqli_query($connection, "INSERT INTO create_user
(name, password, email, sex, school, birth ) VALUES
(
'$field1_name',
'$field2_name',
'$field3_name',
'$field4_name',
'$field5_name',
'$field6_name'
)
");
Use this and you will be good. I hope this has helped you!