PHP/MySQL Help Needed

[Lucky13MN]

I have script that is almost done, I just need
help with one more thing.

I'll describe the relevant structure the best I can, then explain what I need.

TABLE carlot
FIELDS trackpt, id

TABLE cars
FIELD userid, carid

TABLE grpusers
FIELD id

Field id from table carlot = field carid from table cars
Field userid from table cars = field id from table grpusers

The value I need to display is in the field trackpt, what PHP code do I need to get this value (associated with the userid).

What I am trying to do is add that value to other values in the grpusers table.

Any suggestions? I'm sure this isn't difficult for people that work with php and mysql a lot but this is day 3 for me with no formal training and I'm basically tweaking code to make this work.

Any help is greatly appreciated!

Presumably you want an inner join?

Let's assume the table carlot is:

+---------+----+
| trackpt | id |
+---------+----+
| blah    |  1 | 
| wah     |  2 | 
| woot    |  3 | 
+---------+----+

And the table cars is:

+--------+-------+
| userid | carid |
+--------+-------+
|      1 |     3 | 
|      2 |     5 | 
|      3 |     5 | 
+--------+-------+

Now you want to link the two by carlot(id) and cars(userid).

Thus...

mysql> SELECT trackpt, carid FROM carlot
    -> INNER JOIN cars ON carlot.id = cars.userid;
+---------+-------+
| trackpt | carid |
+---------+-------+
| blah    |     3 | 
| wah     |     5 | 
| woot    |     5 | 
+---------+-------+
3 rows in set (0.01 sec)

[Lucky13MN]

Thank you very much, you make it look so easy.

I get this:
Parse error: syntax error, unexpected T_STRING in /home/l1376/public_html/folder/citizens.php on line 4

Line 4 is/was:
mysql> SELECT trackpt, carid FROM carlot

Also, once this is working what code is needed to use 'trackpt' in an equation? Such as HP + trackpt = $challengerpts

Thank you so much...

Thank you very much, you make it look so easy.

I get this:
Parse error: syntax error, unexpected T_STRING in /home/l1376/public_html/folder/citizens.php on line 4

Line 4 is/was:
mysql> SELECT trackpt, carid FROM carlot

Also, once this is working what code is needed to use 'trackpt' in an equation? Such as HP + trackpt = $challengerpts

Thank you so much...

Try:-

<?php
$conn = mysql_connect("localhost","username","yourpassword");
//pick the database to use
mysql_select_db("test",$conn);
//create sql statement
$sql = "SELECT trackpt, carid FROM carlot INNER JOIN cars ON carlot.id = cars.userid";
//execute statement
$result = mysql_query($sql, $conn) or die(mysql_error());
//go through each row in the result set and display data
while ( $newArray = mysql_fetch_array($result) )
{
  //give a name to the fields
  $id = $newArray['trackpt'];
  $testField = $newArray['carid'];
  //echo the results to screen
  echo " $id $testField <br>";
}
?>

Obviously replacing username password with your actual username and password.