help passing variable via form

move3rd · #1 (**permalink**) 04-20-04, 07:58 PM

I'm trying to pass the $artist variable from this form:

PHP Code:


			
<form action="admin_edit_artist.php" method="P0ST">

<select name="artist">

<?       

include "db.php";

      

$sql = "SELECT * FROM `users` WHERE `user_group` = 'artist' ";



$result = mysql_query($sql);



if (!$result) {

   echo "Could not successfully run query ($sql) from DB: " . mysql_error();

   exit;

              }



if (mysql_num_rows($result) == 0) {

    echo "<h4 align=center>Could not find any artists!</h4>";  

   exit;

                                  }



 while ($row = mysql_fetch_array($result))

  {

extract($row);



 echo "<option>".$artist."</option>"; 



  }

mysql_free_result($result);

mysql_close($conn);

?> 

</select> 

<input name="submit" type="submit" value='Select'>

  </form>

to this script:

PHP Code:


			
<? // start the session 

session_start(); 

header("Cache-control: private"); //IE 6 Fix 

?>

 

<?



// Asign session variables

$username = $_SESSION['username'];



$artist = addslashes ($_POST['artist']); 

?>

<table width="100%" border="0" cellpadding="5">

  <tr> 

    <td width="41%">Welcome <? echo "$username"; ?></td>

    <td width="59%"><div align="right"> </div></td>

  </tr>

  <tr> 

    <td height="29"><a href="index.php">Home</a> : <a href="edit_profile.php">Profile</a> 

      : <a href="logout.php"> Log-out</a></td>

    <td><div align="right"></div></td>

  </tr>

</table>

 <? 

      

include "db.php";



if ($_SERVER['REQUEST_METHOD'] == "POST") {

                                              



$sql = "SELECT * FROM `cds` WHERE `artist` = '$artist'";

                                          } 

$result = mysql_query($sql);



if (!$result) {

   echo "Could not successfully run query ($sql) from DB: " . mysql_error();

   exit;

              }



if (mysql_num_rows($result) == 0) {

    echo "<h4 align=center>Could not find any CD's by ".$artist."!</h4>";  

   exit;

                                  }

?>

<table width="700" cellpadding="5" cellspacing="0">

  <tr bgcolor="#F2F2F2"> 

    <td width="119">Title </td>

     

    <td width="82">

<div align="left">Status</div>

    </td>

    <td width="191">Promotion</td>

    <td width="44">Price</td>

    <td width="67">&nbsp;</td>

    <td width="135">&nbsp;</td>

  </tr>

  <? while ($row = mysql_fetch_array($result))

  {

extract($row);

//If CD's are availble print Cd's



    

       echo "<tr><td>".$cd_title."</td>";

       echo "<td>".$cd_status."</td>";

       echo "<td>".$cd_promotion."</td>";

       echo "<td>".$cd_price."</td>";

       echo "<td><div align='right'>";

       echo "<form action='edit_cd.php' method='POST'>";

       echo "<input type='hidden' name='cd_title' value='".$cd_title."'>"; 

       echo "<input name='POST' type='submit' value='Edit'>";

       echo "</form></div></td>";

       echo "<td><form name=\"tracks\" method=\"POST\" action=\"tracks.php\">"; 

       echo "<input type='hidden' name='cd_title' value='".$cd_title."'>"; 

       echo "<input type='hidden' name='artist' value='".$artist."'>"; 

       echo "<input type=\"submit\" name=\"Submit\" value=\"Tracks\"></form>"; 

  }

 

mysql_free_result($result);

mysql_close($conn);

 ?>

  </td>

 </tr>

</table>

I'm getting this error:

Could not successfully run query () from DB: Query was empty

Addict · #2 (**permalink**) 04-20-04, 08:45 PM

PHP Code:


			
echo "<option>".$artist."</option>";

should be...

PHP Code:


			
echo "<option value=\"".$artist."\">".$artist."</option>";

move3rd · #3 (**permalink**) 04-20-04, 09:08 PM

Thanks for checking it out for us but that isnt the problem. <option>$artist</option> the the value is auto set the same as name.

Addict · #4 (**permalink**) 04-21-04, 05:42 AM

Quote:

Originally Posted by move3rd

Thanks for checking it out for us but that isnt the problem. <option>$artist</option> the the value is auto set the same as name.

According the code posted above, its not. You need to have the value attribute in the option tag in order to receive any value for POST. You will still see $_POST['artist'] look like it has been assigned (which it has), but it will be empty. The $artist POST variable is the name of the SELECT box with the OPTION value attribute being the value.

Hopefully that makes sense.

move3rd · #5 (**permalink**) 04-21-04, 06:32 AM

I'm still getting the same error. I've spent 2 days trying to figure this out now!

NeverMind · #6 (**permalink**) 04-21-04, 06:57 AM

I think I know what is the porblem !
these lines always return false !

PHP Code:


			
if ($_SERVER['REQUEST_METHOD'] == "POST") { 

                                               



$sql = "SELECT * FROM `cds` WHERE `artist` = '$artist'"; 

                                       }

so after this IF statment you are asking to excute $sql which wasn't declared because of this IF statment !
so I suggest you change these lines into:

PHP Code:


			
if (isset($_POST['artist'])) { 

$sql = "SELECT * FROM `cds` WHERE `artist` = '$artist'";

}

this one should work !

also I suggest that you don't close the IF statment just after you declare the variable sql, instead close it at the end of the script to avoid useless processing when $_POST['artist'] is not set !

my suggestion is to change it to this:

PHP Code:


			
if (isset($_POST['artist'])) { 

$artist = trim($_POST['artist']);

$sql = "SELECT * FROM `cds` WHERE `artist` = '$artist'";



$result = mysql_query($sql); 



if (!$result) { 

   echo "Could not successfully run query ($sql) from DB: " . mysql_error(); 

   exit; 

              } 



if (mysql_num_rows($result) == 0) { 

    echo "<h4 align=center>Could not find any CD's by ".$artist."!</h4>";   

   exit; 

                                  } 

?> 

<table width="700" cellpadding="5" cellspacing="0"> 

  <tr bgcolor="#F2F2F2"> 

    <td width="119">Title </td> 

      

    <td width="82"> 

<div align="left">Status</div> 

    </td> 

    <td width="191">Promotion</td> 

    <td width="44">Price</td> 

    <td width="67">&nbsp;</td> 

    <td width="135">&nbsp;</td> 

  </tr> 

  <? while ($row = mysql_fetch_array($result)) 

  { 

extract($row); 

//If CD's are availble print Cd's 



     

       echo "<tr><td>".$cd_title."</td>"; 

       echo "<td>".$cd_status."</td>"; 

       echo "<td>".$cd_promotion."</td>"; 

       echo "<td>".$cd_price."</td>"; 

       echo "<td><div align='right'>"; 

       echo "<form action='edit_cd.php' method='POST'>"; 

       echo "<input type='hidden' name='cd_title' value='".$cd_title."'>"; 

       echo "<input name='POST' type='submit' value='Edit'>"; 

       echo "</form></div></td>"; 

       echo "<td><form name=\"tracks\" method=\"POST\" action=\"tracks.php\">"; 

       echo "<input type='hidden' name='cd_title' value='".$cd_title."'>"; 

       echo "<input type='hidden' name='artist' value='".$artist."'>"; 

       echo "<input type=\"submit\" name=\"Submit\" value=\"Tracks\"></form>"; 

  } 



mysql_free_result($result); 

mysql_close($conn); 



}

?>

move3rd · #7 (**permalink**) 04-21-04, 08:21 AM

I'm totaly lost now! I did as you suggested and it's now out-putting a blank page.

I'm totaly lost.

NeverMind · #8 (**permalink**) 04-21-04, 09:44 AM

ok then, just change the first if statment into :

PHP Code:


			
if (isset($_POST['artist'])) {

  $sql = "SELECT * FROM `cds` WHERE `artist` = '$artist'";

}

when blank pages appear it means that some of the IFs is wrong ! which usually makes me rewrite the whole if statment from scratch !

move3rd · #9 (**permalink**) 04-21-04, 10:02 AM

Back to the original error:

Could not successfully run query () from DB: Query was empty

NeverMind · #10 (**permalink**) 04-21-04, 10:15 AM

well, try this if instead:

PHP Code:


			
if ($artist) {

   $sql = "SELECT * FROM `cds` WHERE `artist` = '$artist'";

}