While loop inside a while loop from PDO query

Question

Consider a situation where you have a mysql table FLAGS with a random amount of rows

ID  Language   Flag1               Flag2              Flag3             Flag4 
1   dutch      flanders_flag.png   dutch_flag.png 
2   french     wallonia_flag.png   french_flag.png    morocco_flag.png     
3   english    england_flag.png    ireland_flag.png   america_flag.png  scotland_flag.png

if i want to query these rows and put them into my html i use the while loop because i never know how much rows this table FLAGS has.

<?php
   $flagquery = $db->prepare ("SELECT * FROM flags");
   $flagquery->execute();
   while ($flagrow = $flagquery->fetch(PDO::FETCH_ASSOC)) {
?>
  <div class="col-md-1 col-sm-2 col-xs-6"> 
    <p><?php echo $flagrow['language']; ?></p>
    <p><?php echo $flagrow['flag1']; ?></p>
    <p><?php echo $flagrow['flag2']; ?></p>
    <p><?php echo $flagrow['flag3']; ?></p>
    <p><?php echo $flagrow['flag4']; ?></p>
  </div>
<?php
  }
?>

But as you can see in the FLAGS table you don't always have 4 flags a language so i would think you have to do a while loop inside this previous while loop to echo only the flags that are present in the FLAGS table instead of just echo all the flags even if they are empty.

Are my thoughts right? Or what would be the best way to handle my situation?

I had that in mind to, Thank you for that same idea. But isn't there any shorter way then look if the array key isset? — Peter
– Peter, Commented May 29, 2015 at 11:30
isset() is a short way .. i don't know if there is shorter :) — Omar
– Omar, Commented May 29, 2015 at 11:33
also !empty() is better ... it will return true if the variable is an empty string, false, array(), NULL, “0?, 0, and an unset variable. — Omar
– Omar, Commented May 29, 2015 at 11:37
just tested it and it don't work with the isset(), only with !empty or comparison with an empty string! if you query a column it will ALWAYS be SET even if it is empty. — Peter
– Peter, Commented May 29, 2015 at 11:44

Omar · Accepted Answer · 2015-05-29 11:52:09Z

1

No you don't need a second loop , you can use !empty() . it will return false if the variable is an empty string, false, array(), NULL, “0?, 0, and an unset variable . it will be useful in your case and in case you allow FLAGS to have NULL value.

<?php
 $flagquery = $db->prepare ("SELECT * FROM flags");
 $flagquery->execute();
 while ($flagrow = $flagquery->fetch(PDO::FETCH_ASSOC)) {
?>
<div class="col-md-1 col-sm-2 col-xs-6"> 
<p><?php echo $flagrow['language']; ?></p>
<?php if(!empty($flagrow['flag1'])) echo '<p>'.$flagrow['flag1'].'</p>'; ?>
 <?php if(!empty($flagrow['flag2'])) echo '<p>'.$flagrow['flag2'].'</p>'; ?>
<?php if(!empty($flagrow['flag3'])) echo '<p>'.$flagrow['flag3'].'</p>'; ?>
<?php if(!empty($flagrow['flag4'])) echo '<p>'.$flagrow['flag4'].'</p>'; ?>
</div>
  <?php
}
?>

edited May 29, 2015 at 11:52

answered May 29, 2015 at 11:29

Omar

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priya786 · Accepted Answer · 2015-05-30 04:41:08Z

0

<?php
 $flagquery = $db->prepare ("SELECT * FROM flags");
 $flagquery->execute();
 while ($flagrow = $flagquery->fetch(PDO::FETCH_ASSOC)) {
?>
<div class="col-md-1 col-sm-2 col-xs-6"> 
<p><?php echo $flagrow['language']; ?></p>
<p><?php if($flagrow['flag1']!='') echo $flagrow['flag1']; ?></p>
<p><?php if($flagrow['flag2']!='') echo $flagrow['flag2']; ?></p>
<p><?php if($flagrow['flag3']!='') echo $flagrow['flag3']; ?></p>
<p><?php if($flagrow['flag4']!='') echo $flagrow['flag4']; ?></p>
</div>
  <?php
}
?>

check if variable is empty then it comes in if else not

edited May 30, 2015 at 4:41

answered May 29, 2015 at 11:31

priya786

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2 Comments

priya786 Over a year ago

i will just check if variable is empty then it comes in if else not

Narendrasingh Sisodia Over a year ago

Post it within your answer not to me so further user get to know what you have done and why OP should go for this

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