order by asc / desc problem

nickiehow

I having problem as order by asc and desc not working problem.
By default, order by DESC, when the user click title, it will change to ASC, when the user click the title again, it will change back to DESC

Can anyone advise what went wrong with my code

if (empty($Ssearch)) {$Ssearch = $sqlsearch;}

		$_SESSION["search1"] = $Ssearch;


		if (empty($sort)) {
			$sort = "DESC";
		}
		if ($sort == "ASC") {
			$sort = "DESC";
		} 
		else {
			$sort = "ASC";
		}
		echo $sort;
		if ($sortby) { $Ssearch = "$Ssearch order by $sortby $sort"; }
		//$sqlsearch .= " order by chateaux_name asc, vintage_year desc ";

subwayman

if (empty($sort)) { 
     $sort = "DESC"; 
} 
if ($sort == "ASC") { 
     $sort = "DESC"; 
}  

else { 
     $sort = "ASC"; 
}

Desk checking this logic:

Start End

Null ASC
ASC DESC
DESC ASC

Your problem is the defasult value. You set it to DESC but then reset it to ASC.

Try the following:


if (empty($sort)) { 

 $sort = "DESC"; 

}  else {

 if ($sort == "ASC") { 

     $sort = "DESC"; 

 }  else { 

     $sort = "ASC"; 

 }

}

If a simple bit of code is not working just run through it on paper. That's all I did
to work out what was wrong.

cahva

Theres even shorter way to do that:

if (empty($sort))
	$sort='DESC';
else
	$sort=($sort=="DESC" ? "ASC" : "DESC");

I thought that this might come handy on some other situations too 😉

subwayman

You are right cahva, of course. I used the standard form as the log ic is easier to determine for inexperienced coders. The ternary form can be confusing at first. I don't think I used it for the first couple of years php. Once you've got it, though, it's useful. In reality though all it saves is space in a file. Sometimes , we get too attached to form over function.

nickiehow

Don't work as the $sort alway DESC

can anyone advise me.

subwayman

Then $sort is ALWAYS empty when the code is executed. where in your code is $sort set when the user clicks the title becuase I suspect that is not working.

madwormer2

Try something like $sort = $_GET['sort']; at the top of the page, as I reckon you're assuming that, erm, that thing, erm... is turned on? :S

I'm confusing myself now.

brandondrury

This is day 6 for me on PHP so go easy on me.

Can someone lay out the whole code for this to work properly? I'm missing a few steps and are therefore confused.

The biggest issue being what to define $sort as in the URL.

Thanks,
Brandon Drury

Piranha

I want to get into the competition about typing that if-else as short as possible. Here are my idea:

if ($sort == "DESC")
    $sort = "ASC";
else
    $sort = "DESC";

It is kind of hard to help you out further without having more code. How do you set $sort in the first place? How do you pass it along when clicking the title? Basically we need the code for the whole page, or to be more exact the code that you don't know for sure have got nothing to do with this. Are you confused about the sentence? I am 😛 Just give the whole code and I'm sure it will be possible to work it out.

Installer

Too many spaces and newlines.

if($sort=="DESC")$sort="ASC";else$sort="DESC";

😉

Edit: I'll hold my nose and post this one:

$sort=($sort=='DESC')?"ASC":"DESC";

brandondrury

  if (in_array ($heading, $allowed_order)) {
        echo "<TD><b><a href=\"{$_SERVER['PHP_SELF']}?order=$heading&direction=DESC\">$heading</a> </b></TD>";
    } else { }

This is the URL of my headings.

I pick up $direction using GET.

$direction  = @$_GET['direction']; 
if ($direction  !== "DESC") $direction  = "ASC";

I am able to define the direction of the sorting by typing either DESC or ASC in the "direction= " part in the URL above.

Just for fun / testing I defined direction=7 in the URL and the results turn out ASC.

However, when I click on my heading links, I am not able to switch from ASC / DESC.

Here's a URL if it helps:
http://www.recordingreview.com/soundcard/soundcard_search/browse_new.php

Here's my code:

<body>
<?php

if (isset($_POST['advanced'])) { 
    // define variables from advanced form 
	$input=intval($_POST['inputs']); 
	$preamp= intval($_POST['preamps']); 
	$connections=$_POST['connection'];
	$hizinputs= intval($_POST['hizinput']); 
	$midis=$_POST['midi'];
	$softwares=$_POST['software'];
	$monitorings=$_POST['monitoring'];
	$prices=$_POST['price'];
	$bundled=$_POST['bundled'];
	$SPDIF=$_POST['SPDIF'];
	$AES=$_POST['AES'];
	$ADAT=$_POST['ADAT'];
	$MAC=$_POST['MAC'];
	$PC=$_POST['PC'];
    echo "We used the advanced form";
} else { 
    // define variables from session variables 
	$input=intval($_SESSION['inputs']); 
	$preamp= intval($_SESSION['preamps']); 
	$connections=$_SESSION['connection'];
	$hizinputs= intval($_SESSION['hizinput']); 
	$midis=$_SESSION['midi'];
	$softwares=$_SESSION['software'];
	$monitorings=$_SESSION['monitoring'];
	$prices=$_SESSION['price'];
	$bundled=$_SESSION['bundled'];
	$SPDIF=$_SESSION['SPDIF'];
	$AES=$_SESSION['AES'];
	$ADAT=$_SESSION['ADAT'];
	$MAC=$_SESSION['MAC'];
	$PC=$_SESSION['PC'];
	echo "We used the wizard tutoral thingy";
} 

//Get the page number to show 
/* set the allowed order by columns */
	$page=$_GET["page"]; 
	$default_sort = 'price';
	$allowed_order = array ('brand', 'model','inputs', 'preamps', 'connection', 'hizinput', 'midi', 'software', 'monitoring', 'price', 'PC', 'Mac', 'SPDIF', 'AES', 'ADAT', );

/* if order is not set, or it is not in the allowed
 * list, then set it to a default value. Otherwise, 
 * set it to what was passed in. */
if (!isset ($_GET['order']) || 
    !in_array ($_GET['order'], $allowed_order)) {
    $order = $default_sort;
} else {
    $order = $_GET['order'];
}


/*  test  */
$direction  = @$_GET['direction']; 
if ($direction  !== "DESC") $direction  = "ASC";



/* connect to db */
edited

/* setup math for limit */

If($page == "") $page=1; //If no page number is set, the default page is 1 
$Pagelimit=($page-1)*$Limit;
echo "$Pagelimit is the pagelimit";
$Limit = 5; //Number of results per page 

/* construct and run our query */
$query = "SELECT * FROM test5 WHERE inputs >= $input AND 
preamps >= $preamp AND hizinput >= $hizinputs AND connection LIKE '$connections%' AND midi LIKE '$midis%'    AND bundled LIKE'$bundled%' AND monitoring LIKE '$monitorings%'  AND price LIKE '$prices%'  AND SPDIF LIKE '$SPDIF%' AND AES LIKE '$AES%' AND ADAT LIKE '$ADAT%' AND MAC LIKE '$MAC%' AND PC LIKE '$PC%' ORDER BY $order $direction LIMIT $Pagelimit,$Limit";
$result = mysql_query ($query);




/* make sure data was retrieved */
$numrows = mysql_num_rows($result);
if ($numrows == 0) {
    echo "No data to display!";
    exit;
}



/* calculate pages */

$NumberOfPages=ceil($numrows/$Limit); 
	echo "<br>Number of pages: $NumberOfPages";


/* now grab the first row and start the table */
$row = mysql_fetch_assoc ($result);
echo "<TABLE border=1>\n";
echo "<TR>\n";

foreach ($row as $heading=>$column) {
    /* check if the heading is in our allowed_order
     * array. If it is, hyperlink it so that we can
     * order by this column */


if (in_array ($heading, $allowed_order)) {
    echo "<TD><b><a href=\"{$_SERVER['PHP_SELF']}?order=$heading&direction=7\">$heading</a> </b></TD>";
} else { }                
echo "\n";
}
echo "</TR>\n";

/* reset the $result set back to the first row and 
 * display the data */
mysql_data_seek ($result, 0);
while ($row = mysql_fetch_assoc ($result)) { ?> 

<?php

   if(($i % 2) == 1)  //odd
     {echo "<tr class=\"td1\">";}
   else  //even
     {echo "<tr class=\"td2\">";}

?> 

<td><?php echo $row['brand'] ?></td> 
<td><h5><a href="product.php?id=<?php echo $row['id'] ?>"><?php echo $row['model'] ?></a> </h5></td>
<td bgcolor=""><? echo $row['inputs']; ?></td>
<td><? echo $row['preamps']; ?></td>
<td><? echo $row['hizinput']; ?></td>
<td><? echo $row['connection']; ?></td>
<td><? echo $row['midi']; ?></td>
<td><? echo $row['software']; ?></td>
<td><? echo $row['monitoring']; ?></td>
<td><? echo $row['price']; ?></td>
<td><? echo $row['PC']; ?></td>
<td><? echo $row['Mac']; ?></td>
<td><? echo $row['SPDIF']; ?></td>
<td><? echo $row['AES']; ?></td>
<td><? echo $row['ADAT']; ?></td>



<? $i = $i + 1;
  ?>
 </tr>  <? }
echo "</TABLE>\n";

?> 
</body>

anoopmail

it seems functioning on ur site ..