Question

Ok. So here’s what I want to do.

I would like to make it so that a piece of code, grabs the contents form the variable

$_SESSION['user']

and find the row in the MySQL table the contains that variable.

Then I want it to edit a row that already has information in it by grabbing information from another variable such as

$_POST['country']

I have no idea how to do this. Is there a simple way.

The MySQL info is:

 host: 'localhost'
 user: 'root'
 pass: ''
   db: 'database'
table: 'accounts'

Answer 1

You can do it something like this:

mysql_query(sprintf("UPDATE accounts SET country='%s' WHERE user_id='%s'",
    mysql_real_escape_string($_SESSION['country']),
    mysql_real_escape_string($_SESSION['user'])
));

Just replace the field/table with their respective names.

The actual SQL you’re learning here is:

UPDATE table SET field='value', field2='value2', ... WHERE field3='value3', ...

Make sure to always sanitize the input as done with mysql_real_escape_string; Not doing this leaves a hole in your system which is very easy to exploit – and at worst costs you your database to be dropped, sensitive data to be exposed or a hacker to succesfully authorize himself as another user.

And if you havn’t connected to the database, you do this (before running the query):

mysql_connect("localhost", "root", "");
mysql_select_db("database");