Using Link Data

[obrienkev]

Hi all,

I have numerous links, each with unique values. For simplicity purposes I'll use two links...(each taken from separate queries.)

<a href="view_files.php?ida='.$array['id'].'">'.$array['name'].'</a>
 <a href="view_files.php?idb='.$array['id'].'">'.$array['name'].'</a> 

When a certain link is selected the relevant code from the switch statement should be used.
However, the first one is always used. Why is this?

 if(!empty($_GET))
 {
 // Connect to database
 include('../../../db_connect.php');
     
 // declare variables 
 $ida = $_GET['ida'];
 $idb = $_GET['idb'];
 
 // check which file selected
 switch(TRUE)
 {
 case ('$ida'):
     $query   = "SELECT name, type, size, content ".
              "FROM mergers ".
              "WHERE id = '$ida'";
     echo $query;
     break;
         
 case ('$idb'):
     $query   = "SELECT name, type, size, content ".
              "FROM centralised_archive.mergers ".
              "WHERE id = '$idb'";
     echo $query;
     break;
 }
 
 $result  = mysql_query($query) or die(mysql_error()); 

[FrlB]

Try

echo '$ida'; 

The variable won't be evaluated within single quote strings. And as a non-empty string it is true.

[paulyG]

Switch generally analyses one variable, if its not true it goes to the next one...

If you are intent on using a switch (you may have your reasons) then I would set something in the url:

t for "type", v for value;

<a href="view_files.php?t=1v='.$array['id'].'">'.$array['name'].'</a>

....


$v=(int)$_GET['v']; //make sure its an int!


Then analyse $t in your switch:

switch((int)$_GET['t'])  //make sure its an int!
{
case (1):
    $query   = "SELECT name, type, size, content ".
             "FROM mergers ".
             "WHERE id = '$v'";
    echo $query;
    break;
        
case (2):
    $query   = "SELECT name, type, size, content ".
             "FROM centralised_archive.mergers ".
             "WHERE id = '$v'";
    echo $query;
    break;
} 

Then do a "default" if the no. isnt recognised

Switch generally analyses one variable, if its not true it goes to the next one... So its checking to see if $t==1 or goes off to next one, and so on till it gets to the default.

Paul

EDIT

If its a monster switch you might want to isolate the bit thats changing:

case (1):
      $querybit  = "FROM mergers ";
      break;
case (2):
    $querybit   = "FROM centralised_archive.mergers ";
    break;
}

$query = "SELECT name, type, size, content ".
$query.=$querybit;
$query.="WHERE id = '$v'";

echo $query; 

Hope that helps you...

[obrienkev]

Hi paulyg. Will $t always be set to 1 for each link??

[spikeZ]

Hi Kev,

Just how I would approach it....

if(!empty($_GET))
{
// Connect to database
include('../../../db_connect.php');
    
// declare variables 
$var = isset($_GET['ida']) ? $_GET['ida'] : $_GET['idb'];
// check which file selected
switch($var)
{
case (@$_GET['ida']):
    $query_table   = " mergers ";
    $var = $_GET['ida'];
    break;
        
case (@$_GET['idb']):
    $query_table   = " centralised_archive.mergers ";
    $var = $_GET['idb'];  
    break;
}

$query = "SELECT name, type, size, content ".
             "FROM ". $query_table ."
             WHERE id = ". $var;
#$result  = mysql_query($query) or die(mysql_error());
echo $query;
} 

Mike

[obrienkev]

Hi Mike,

So if I have 3 or 4 variables would they be set as...

$var = isset($_GET['ida']) ? $_GET['ida'] : $_GET['idb'] ? $_GET['id2a'] : $_GET['id2b'] ? $_GET['id3'];