querying multiple tables with multiple GET functions using 1 query - php

Question

I am trying to query 6 separate tables in my mysql database, the structures are as follows;
item
itemitemid | item | description | brand | date | time | path |
actor
actoractorid | name | actorthumb | bio |
brand
brandbrandid | brandname | description | image |
movie
moviemovieid | title | genre | year | moviethumb | synopsis|
user
userid | name | surname | email | password |
request
requestid | userid | itemid | brandid | movieid | actorid | content | requestdate |
By clicking a link to a page called style.php using the get commands I can view the request and the info within it by pulling it from the joined tables. For example where the requestid=1 I can see the movie in the request, the actor in the movie, the item of clothing they were wearing and its brand. By using the following 4 querys;
Movie
$requestid = $_GET['requestid'];
$query = "SELECT * FROM movie, request WHERE movie.movieid =
request.movieid and requestid = ".$requestid;
Actor
$requestid = $_GET['requestid'];
$query = "SELECT * FROM actor, request WHERE actor.actorid =
request.actorid and requestid = ".$requestid;
Item
$requestid = $_GET['requestid'];
$query = "SELECT * FROM item, request WHERE item.itemid =
request.itemid and requestid = ".$requestid;
Brand
$requestid = $_GET['requestid'];
$query = "SELECT * FROM brand, request WHERE brand.brandid =
request.brandid and requestid = ".$requestid;
Therefore I would like to combine the 4 querys above into 1 single query that would allow me to show all the info, including querying the user and request tables to show who logged the request, please advise?

Answer 1

SELECT * FROM request r
INNER JOIN movie m ON m.movieid = r.requestid
INNER JOIN actor a ON a.actorid = r.requestid
INNER JOIN item i ON i.itemid = r.requestid
INNER JOIN brand b ON b.brand_id = r.requestid
WHERE r.requestid = {your request id}
Of course, if there is a possibility one of the joins will fail (e.g., a movie without a brand) then use a left join instead.
Also, isnt a bit strange that all of your primary keys are equal? You could get away with never selecting from the request table if this is truly the case:
SELECT * FROM movie m
INNER JOIN actor a ON a.actorid = m.movieid
INNER JOIN item i ON i.itemid = m.movieid
INNER JOIN brand b ON b.brand_id = m.movieid
WHERE m.movieid = {your request id}

Answer 2

First: if you are not using mysql_real_escape_string() on your database inputs, you are asking for a LOT of trouble.
Second: SELECT * should not be used this way... you can get duplicate column names which will make your life very difficult very quickly. It takes a bit more up-front time, but specify the columns you want to return.
Third: you can join all of these, if you want to get a lot of columns back, and a lot of rows with duplicate data:
$requestid = mysql_real_escape_string($_GET['requestid']);
$query = "select r.requestid, m.*, a.*, i.*, b.* FROM request r INNER JOIN movie m ON m.movieid = r.movieid INNER JOIN actor a ON a.actorid = r.actorid INNER JOIN item i ON i.itemid = r.itemid INNER JOIN brand b ON b.brandid = r.brandid WHERE r.requestid = $requestid";
you also might want to use LEFT OUTER JOIN if some of these rows won't join up.