Sort by asc/desc

Viduus

I've got a table set up to show results, with the headers links to sort_by, and supposed to alternate from ASC to DESC if clicked twice, but it always shows ASC...
Could someone tell me what's wrong in this snippet?

printf("<th><a href=\"%s?sort_by=email&last_sort_by=$sort_by&is_asc=$is_asc\">Email</a></th>\n", $_SERVER['PHP_SELF'] );
	echo '</tr>';
$sort_by = $_GET['sort_by']; 
$last_sort_by = $_GET['last_sort_by']; 
$is_asc = $_GET['is_asc']; 

if (strlen($sort_by) == 0) 
{  

$sort_by = 'mem_id'; 
$is_asc = '1'; 
} 
else if ($sort_by == $last_sort_by) 
{ 
$is_asc = ($is_asc == '1' ? '0' : '1'); 
} 
else 
{ 
$is_asc = '1'; 
}

$sql = "SELECT * FROM memberlist ORDER BY " . $sort_by . $asc; 

$result = mysql_query( $sql );

Thanks in advance. :}

planetsim

I dont see $asc being defined anywhere in that script.

zapa

Mysql defalt is ASC.

so you are btter off setting ti to DESC maybe?

"SELECT * FROM memberlist ORDER BY $sort_by $asc";

you qurey look like to me
"SELECT * FROM memberlist ORDER BY something 1"
when it should read

"SELECT * FROM memberlist ORDER BY something ASC"

Viduus

Right, and right...

I tried adding this:


if ($is_asc = '1') {
	$asc = ' ASC'; }
else {
	$asc = ' DESC'; }

and changing the line:

$sql = "SELECT * FROM memberlist ORDER BY  " . $sort_by . $asc;

$sql = "SELECT * FROM memberlist ORDER BY  $sort_by  $asc";

but it still does nothing...
edit
Sorting by column works still, but ascending/descending doesn't.

planetsim

Why dont you echo your SQL query to make sure its getting the correct values?

Viduus

  echo $is_asc . $last_sort_by . $asc . $sql;

after one click on 'Name' yields:
1 ASCSELECT * FROM memberlist ORDER BY name ASC

after a second click it reads:
1name ASCSELECT * FROM memberlist ORDER BY name ASC

So $is_asc is not being parsed somehow...? Should I possibly remove the quotes from the 0 - 1 values, to make it a numerical toggle? grasping at straws

edit

No matter what I do, $is_asc is !always! set to 1... so obviously there's something wrong with my logic but I don't see it. :/

zapa

i see you issue...

should be...
if ($is_asc == '1') {
$asc = ' ASC'; }
else {
$asc = ' DESC'; }

insted of one = use two == for checking is

Viduus

Right, I caught that after posting this, but it still didn't work.

I made a few small changes, and I can now get it from ascending to descending, but it doesn't reset. I guess the line $is_asc = ($is_asc == 0 ? 1 : 0); isn't working right, so I guess I'm going to have to use a case 0 case 1 or another if else set, to reset the $last_sort_by value...

zapa

hey if you checking 0 and 1 use empty() if you want.

works liek this..

this will do soemthing if $check = 0 or blank
if(empty($check)){
// do something.
}

ise !empty for cehck if its 1 or set