user levels

dazednconfused · July 7th, 2003, 07:25 AM

Think this is probably just something stupid that im doing wrong, but..

I have a administrator section on my site and am trying to set up two user levels, moderator and administrator. I have an idea of how to do it, im thinking search database for user level where username = $username (the one theyre logged in as)

Code:
include("includes/connect.php");

//start sql query
$sql=@"SELECT user_level FROM users WHERE username = '$username'";

$result=mysql_query($sql,$link_id);

if ($result =="administrator"){ //display stuff here }

The problem is if I print $result is just says "Array" rather than the search result. The query seems to be working ok, do I have to do something to the result befor I can check if it is equal to "administrator"?

nikolai · July 7th, 2003, 02:38 PM

Remember that $result is a result identifier, not the actual text of your query. You still have to fetch the actual data from the result set before you play with it.

Read the documentation page online for details:
http://www.php.net/mysql_query

Code:

$result = mysql_query($sql);

if($result != FALSE)
{
    $lvl = mysql_result($result, 0); // http://www.php.net/mysql_result
    if($lvl == "administrator")
    {
        // display stuff here
    }
}

Take care,

Nik
http://www.bigaction.org/

nikolai · July 7th, 2003, 02:49 PM

One more thing:

Personally, I also think it's best to use a numeric id for your user levels. Add a new table, user_levels, to your database. The table will just be a unique ID field and a text description.

The user level stored in the users table will be the numeric ID, not the text. This is called "normalizing" your database, which in the long run increases efficiency and decreases storage space.

Take, for example, a users table with 5 administrators. Your database table takes up at least 13 bytes for each user to store the text "administrator" in the user levels, a total of 65 bytes. Compare that to the 5 bytes it would take to store a 1-byte integer that matches the numeric ID of the user_levels table.

This is how it'd all break down:

Code:

table: user_levels
id     desc
1      basic user
2      moderator
3      administrator
...

table: users
id     username         user_level_id
1      nikolai          1
2      dazednconfused   3
...

Now, your query will be something:

Code:

$query = "SELECT desc from user_levels
           INNER JOIN users ON
                 user_levels.id = users.user_level_id
             AND users.username = $username";

If you're not comfortable using JOINs, use this equivalent query:

Code:

$query = "SELECT user_levels.desc from users, user_levels
           WHERE users.username = $username
             AND users.user_level_id = user_levels.id";

Make sense?

There's lots of information and tutorials out there about efficient database design, normalization, joins, etc. Happy hunting!

Take care,

Nik
http://www.bigaction.org/

dazednconfused · July 8th, 2003, 04:29 AM

Thanks, that was most helpfull, I hadnt really thought about doing it that way.