How to insert values in database if it set foreign key? - php

Question

<?php
if(isset($_GET['email']) && !empty($_GET['email']))
{
$email = mysql_real_escape_string($_GET['email']);
$sml="UPDATE USERS SET password=$_POST[password] where email='$email' ";
$account=mysql_query("INSERT INTO ACCOUNT(email) SELECT email from USERS WHERE email='$email' ") or die('Error:' .mysql_error());
if (mysql_query($sml,$con))
{
header('Location: ../home.html');
}
else{
die('Eror: ' . mysql_error());
}
}
else
{die('Eror: ' . mysql_error());}
mysql_close($con);
?>
How to insert email in account table its an foreign key for the account table.
I want to insert same email value to the account table for the other table reference.

Answer 1

You have to add user/s first. You can't add a record into Accounts table if you don't have a matching record in the parent(Users) table.
That is how foreign key constraint works. For example if you have a record in Users table with user_id = 1, you are only allowed to have records with user_id = 1 in the Accounts table. And so on...
Hint 1:
Try not to put $_POST['key'] directly into query because that makes it vulnerable to sql injection.
Hint 2:
Use exit after header function.