Question

I am trying to create loop inside of a HEREDOC in php. I know that it is not possible to do so, but it was the best way for me to tell what I need help for..
This is my code:

<?
$sth = $dbh->prepare("SELECT field1, field2 FROM table WHERE id = '".$_GET['id']."'");
$sth->execute();
echo <<<HERE_DOC
    [
    while($row = $sth->fetch()){ 
        echo '{"optionValue":"'.$row['field1'].'", "optionDisplay": "'.$row['field2'].'"},'; 
    }
    ]
HERE_DOC;
?>

and it tells me this

 Parse error: syntax error, unexpected T_ENCAPSED_AND_WHITESPACE, expecting T_STRING or T_VARIABLE or T_NUM_STRING in /public_html/test.php on line 7

I think it returns this because it is not possible to create a loop inside a HEREDOC – but how do I do this otherwise..?

The script is driving by AJAX with this script:

<script type="text/javascript">
$(function(){
  $("select#state").change(function(){
    $.getJSON("test.php",{id: $(this).val(), ajax: 'true'}, function(j){
      var options = '';
      for (var i = 0; i < j.length; i++) {
        options += '<option value="' + j[i].optionValue + '">' + j[i].optionDisplay + '</option>';
      }
      $("select#city").html(options);
    })
  })
})
</script>

and the original test.php is like this:

if ($_GET['id'] == "1234") {
  echo <<<HERE_DOC
    [
    {"optionValue":"000", "optionDisplay": "a"},
    {"optionValue":"300", "optionDisplay": "s"},
    {"optionValue":"600", "optionDisplay": "d"},
    {"optionValue":"700", "optionDisplay": "cr"},
    {"optionValue":"500", "optionDisplay": "Gı"},
    {"optionValue":"400", "optionDisplay": "K"},
    {"optionValue":"800", "optionDisplay": "S"},
    {"optionValue":"900", "optionDisplay": "ik"},
    {"optionValue":"350", "optionDisplay": "Tu"}
    ]
HERE_DOC;
else if ($_GET['id'] == "2345") { etc......

The thing is that I already have all the data in an SQL database, and I would like to just return the data based on the id from previous select list since there is a lot of options.

Answer 1

Don’t make the JSON yourself, use json_encode.

<?
$json = array();
$sth = $dbh->prepare("SELECT field1, field2 FROM table WHERE id = '".$_GET['id']."'");
$sth->execute();
while($row = $sth->fetch(PDO::FETCH_ASSOC)){ // added PDO::FETCH_ASSOC
    $json[] = array(
        'optionValue' => $row['field1'],
        'optionDisplay' => $row['field2']
    );
}
echo json_encode($json);
?>

P.S. Don’t use $_GET directly like that. You’re vulnerable to SQL injection. You’re already using PDO, use it correctly. You should do it like this:

$sth = $dbh->prepare("SELECT field1, field2 FROM table WHERE id = ?");
$sth->execute(array($_GET['id']));