PHP + MySQL Display Value from multiple rows in one row

I do not know if you have specific restrictions or limitations but I do not usually mix business logic with presentation logic. In this case i would prefer don't create a temp table (maybe a view is better) because you use it in order to show a table on the presentation layer. I assume i have a data model like this (i repeat: i don't know if it is your case)

TABLE "PILOTI"

+--------+-------------+
|  ID    | NOME        |
+--------+-------------+
|   1    | Colin McRea |
+--------+-------------+
|   2    | Carlos Sainz|
+--------+-------------+

TABLE "GARE"

+--------+-------------+
|  ID    | NOME        |
+--------+-------------+
|   1    | Montecarlo  |
+--------+-------------+
|   2    | Argentina   |
+--------+-------------+
|   3    | Svezia      |
+--------+-------------+

TABLE "CAMPIONATO" (n-n => relation table between GARE and PILOTI)

+--------+-------------+-------------+-------------+
|  ID    | ID_PILOTA   |  ID_GARA    | PUNTEGGIO   |
+--------+-------------+-------------+-------------+
|   1    |    1        |    1        |     43      |
+--------+-------------+-------------+-------------+
|   2    |    1        |    2        |     33      |
+--------+-------------+-------------+-------------+
|   3    |    2        |    1        |     15      |
+--------+-------------+-------------+-------------+
|   4    |    2        |    2        |     18      |
+--------+-------------+-------------+-------------+

With this query, i retrieve for each driver, the points reached every championship

SELECT P.NOME, G.NOME, C.PUNTEGGIO
FROM CAMPIONATO C
JOIN PILOTI P ON P.ID = C.ID_PILOTA
JOIN GARE   G ON G.ID = C.ID_GARA

You can add a "WHERE" condition in order to filter for a single driver (or single championship). For example, if you have 15 drivers, you can retrieve the points reached to each driver (for each championship) with only 15 query adding

WHERE P.ID = :id_pilota

to the prevoious query.

You may also create a view with this query and calculate the total points but i prefer to do this in PHP and not in MySQL. I.E. (PSEUDO-CODE)

foreach($driver){
 queryToGetPoints();
 foreach($championship){
   $totalPoints+=$points;
 }
 printHtmlRow();
}

However, With MySql the ordering is more simply

SELECT P.NOME,SUM(C.PUNTEGGIO) AS TOTALE
FROM CLASSIFICA C
JOIN  PILOTI P ON P.ID = C.ID_PILOTA
GROUP BY C.ID_PILOTA 
ORDER BY TOTALE ASC

In order to update the points, after a championship is closed, you can insert in "CAMPIONATO" table, for each driver, a new row whit his own ID, the ID of the championship and the points reached.

I.E.

INSERT INTO CAMPIONATO (ID_PILOTA, ID_GARA, PUNTEGGIO) VALUES (1,3,18)

=> McRea reached 18 points in Svezia

You may also create a table "CLASSIFICA" whit two fields: ID_PILOTA e TOTALE then create a trigger on "CAMPIONATO" table "after insert" in order to update the CAMPIONATO.TOTALE field with the sum of the old value + the points inserted.

So, you can see there is more than one way in order to do what you want. My suggestion is: if one more query help you to get your code more simply, use it even if there is a computational overhead (multiple queries in nested loop in this case). Hope this help you. Good luck!