[FIXED] How do I show a user's credit based on their session

Issue

I'm developing a simple LAMP app where users can credit their account using Paypal. I suspect this is a simple issue, but have spent quite a while experimenting to no avail and would appreciate any thoughts:

---

System has a user management system working fine using sessions, but I can't get it to display the current user's credit.

But I've been trying things along the lines of:

$result = mysql_query("
SELECT *
FROM users
INNER JOIN account
ON account.UserID=account.UserID
ORDER BY account.accountID");

while($_SESSION['Username'] = $row['Username'] ) { echo $row['Username']; echo $row['Credit']; }

I suspect the while statement is invalid, but I want it to echo username and credit where the current session username = the username stored in the database.

Thanks so much for taking a look - very much appreciated.

Solution

Okay there is actually a lot wrong with your code that can not be fixed by you as you have obviously no knowledge of php at all.
But let me explain this so you can get a good understanding of what you did wrong:

First of all, your mysql statement is just wrong. Why do you join a field on itself? You won't get the corresponding users <-> account rows because users is never actually joined.
In addition to that, if you want to fetch a single row (you only want one because you only want to echo the data of one user, fetching more is only heavier in resources), tell mysql to do that. A simple example would be "WHERE a="b" LIMIT 1 (select only row where a is equal to "b", return after finding the first).

Now, to read something from your query, you need to fetch the corresponding data.
You can do that by using mysql_fetch_assoc / mysql_fetch_array / mysql_fetch_object. This would look something like this: $data = mysql_fetch_array($query);. In this case, you don't need to use a while() loop as you only have one row. A while loop is only necessary if you want to work with more then one row.

The rest of your code would be correct, though you don't need to call echo twice. You can simply connect both variables with a ".": echo $row['Username'].$row['Credit'];.
If you want to insert a space in between, connect it with another dot: echo $row['Username']." ".$row['Credit'];.

Answered By - Robin