how do I say..if my variable is blank or empty do xyz?

[futrose]

I have been trying to fix this code snippet because I need to do something different if my variable is empty.

$result = mysqli_query($link, "Select eldercatid from eldercategory where elderid = '$id'");
if (!$result)
{
$error = 'Error fetching elder details ' . mysqli_error($link);
include '../../includes/error.php';
exit();
}

while ($row = mysqli_fetch_array($result))
{
	$selected[] = array('eldercatid' => $row['eldercatid']);
}

 

here is the code being used on the page using the variable

foreach ($selected as $s);	
if ($ec['id'] == $s['eldercatid'])
{
echo 'selected = "yes"';
}

 

I need my $selected variable to be equal to anything if $row['eldercatid'] is blank or empty because on the next page I have a call to use $selected but I am getting an error that says undefined variable: selected.

 

I have tried all kinds of lines using if empty and if ($row['eldercatid'] != '') among other stuff but haven't had any luck.  I know this probably pretty basic stuff, I just don't know it well enough yet. 

 

Thanks for your help.

[phpSensei]

It means you havn't defined $selected as an array outside the while loop. Also your going about this the wrong way, you can simply check for a match inside the while loop instead of putting inside an array, or you can even do a simple

 

[futrose]

a simple what? You left me hanging.

[phpSensei]

sorry haha,

 

You can do a simple mysql query to check the column field with $selected, and do a mysql_num_rows to check for the number of fields returned.

[futrose]

can you give me an example...?  I understand the logic behind your answer but I'm not sure what the code would be to do it.

[phpSensei]

<?php
$result = mysqli_query("SELECT * FROM `eldercategory` WHERE `elderid` = '$id'");

while($row = mysql_fetch_array($result)){


	if($ec['id'] == $row['elderid']){

		// selected does equal to the $ec['id']

	}else{


	        // does not equal

	}	

}

?>

[trq]

That was a terrible example.

 

<?php
$id = mysql_real_escape_string($ec['id']);
if ($result = mysqli_query("SELECT elderid FROM eldercategory WHERE elderid = '$id'")) {
  if (mysql_num_rows($result)) {
    // match found
  } else {
    // no match found
  }
}

 

?>

[phpSensei]

Thorpe, how can you quickly assume $ec['id'] is directly from an HTTP VAR and not inside a while loop for another query? I simply used he own code so that he may change it himself if that was the case. I understand the second code he posted was outside the while loop, but I just thought he went about it the wrong way. If i had made a terrible example, thank you for posting a better one, I always appreciate that and so do the members.

[futrose]

I think I may have been a little confusing.  Let me explain better.  I have 2 files, index.php and elders_modify.php

Here is the code from index.php as I have it right now.

$result = mysqli_query($link, "Select * from eldercategory where elderid = '$id'");
if (!$result)
{
$error = 'Error fetching elder details ' . mysqli_error($link);
include '../../includes/error.php';
exit();
}

while ($row = mysqli_fetch_array($result))
{
if($id != $row['elderid'])
{
$selected = '0';
}
else
{
	$selected[] = array('eldercatid' => $row['eldercatid']);
}

}

 

the $id is pulled when an admin clicks on a staff member to edit this code tells the elders_modify.php file which categories in the drop down menu to mark as "selected".  The code works fine when a staff member has a category assigned to them already.  If a staff member does not have a category assigned yet than $selected is empty because $eldercatid is empty.

 

here is the code from elders_modify.php

...
<td>Staff Category:</td><td><select name="eldercatid[]" multiple>
<?php foreach ($eldercat as $ec): ?>
<option value="<?php echo $ec['id']; ?>" 
<?php if ($action == 'elder_edit')
{

foreach ($selected as $s);	
if ($ec['id'] == $s['eldercatid'])
{
echo 'selected = "yes"';
}

}
echo '>';
echo $ec['category']; ?></option>
<?php endforeach; ?>
</select>

 

all I need to do is give $selected a value to carry over from index.php to elder_modify.php when a staff member has no category assigned yet.  For some reason my

$selected = '0';

isn't recognized.

[futrose]

I got it to work... thanks for your help guys.  I appreciated the examples.  I just had to tweak them a bit but all is good for now.  Maybe one day I'll have answers to post instead of just questions.

[trq]

Thorpe, how can you quickly assume $ec['id'] is directly from an HTTP VAR and not inside a while loop for another query?

 

It wasn't necessarily the usage of mysql_real_escape_string that I was harping on about. More the fact that you can (and should) do the actual comparison in your query.