Array_unique function question?

Databases
1

Hi Everyone,

I want to display the vehicles every user is selling but for some reason I’m getting duplicate information. I think the answer to my question is the array_unique function but I’m having a hard time trying to figure out where the function should go? Any tips would be great, thanks!

http://www.whatsmyowncarworth.com/for-sale/mysql/mysql-command.php

<?php
include_once "init.php";

echo "<table border='1'>";
echo "<tr> <th>User ID</th> <th>First Name</th> <th>Last Name</th> <th>Car Desc ID</th> <th>Price</th>  <th>Mileage</th> <th>Transmission</th> <th>Color</th> <th>Year</th> <th>Make</th> <th>Model</th> </tr>";

$query = "SELECT users.user_id, users.firstname, users.lastname, prices.car_desc_id, prices.price, \
"
    . "\
"
    . "prices.mileage, prices.transmission, prices.color, car_desc.year, car_desc.make, car_desc.model\
"
    . "\
"
    . "FROM users, prices, car_desc\
"
    . "\
"
    . "WHERE prices.car_desc_id LIMIT 0, 30 ";	

// $result = array_unique($query);	

// $query = "SELECT * FROM car_desc ORDER BY id ASC";
$thedude = mysql_query($query) or die(mysql_error());
// $result = array_unique($thedude);
while ($row = mysql_fetch_array($thedude)) {

    $user_id = ($row['user_id']);
	$firstname = ($row['firstname']);
    $lastname = ($row['lastname']);
    $car_desc_id =  ($row['car_desc_id']);
    $price = ($row['price']);
    $mileage = ($row['mileage']);
	$transmission = ($row['transmission']);
	
	$color = ($row['color']);
    $year = ($row['year']);
	$make = ($row['make']);
    $model = ($row['model']);


	// keeps getting the next row until there are no more to get
	 /*while ($row = mysql_fetch_array($result))*/ {
		// Print out the contents of each row into a table
?>
2

If your query is bringing back duplicate rows from your database then that is where you should be looking first in order to eliminate them.

See if you can do this using the mysql DISTINCT keyword or something:



$query = "SELECT users.user_id
, users.firstname
, users.lastname
, prices.car_desc_id
, prices.price
, prices.mileage
, prices.transmission
, prices.color
, car_desc.year
, car_desc.make
, car_desc.model
FROM users, prices, car_desc 
WHERE prices.car_desc_id LIMIT 0, 30 ";

I reformatted your query so it is easier to read and understand for others.

I think the problem lies in you doing joins but not doing so implicitly with JOIN statements.

You could ask to have this moved to the sql forum, using PHP to remove the duplicates is not the way to go about this.

3

Hi Cups,

Thanks for your help. I tried the DISTINCT keyword and nothing has changed.

I would be interested in moving this question to the mysql forum. Who would I need to ask?

Thanks everyone!

4

the duplicates are coming from your query

look up cross join

it’s caused by this –

FROM users, prices, car_desc

every user is matched with every price, and every one of those combinations is matched with every car_desc