Check for a null value from a database -- failing - php

Question

I am retrieving 3 fields from a database, and by default, only the username field will have content. The other information will be added in from a user application. I want to show the field as "No Info" if there is no entry in the field. I am trying to use both empty() and is_null() to no avail. A var_dump of $row['firstname'] and $row['lastname'] returns NULL in both cases.
<?php
if (isset($_GET["subcat"]))
$subcat = $_GET["subcat"];
if (isset($_GET["searchstring"])) {
$searchstring = $_GET["searchstring"];
}
$con = mysqli_connect("localhost","user","password", "database");
if (!$con) {
echo "Can't connect to MySQL Server. Errorcode: %s\n". mysqli_connect_error();
exit;
}
$table = 'USERS';
$brand = '%' . $searchstring . '%';
$rows = getRowsByArticleSearch($brand, $table);
echo "<table border='0' width='100%'><tr>" . "\n";
echo "<td width='15%'>Username</td>" . "\n";
echo "<td width='15%'>Firstname</td>" . "\n";
echo "<td width='15%'>Surname</td>" . "\n";
echo "</tr>\n";
foreach ($rows as $row) {
if (is_null($row['firstname']) || $row['firstname'] == "") {
$row['firstname'] == "No Info";
}
if ($row['lastname'] == null || $row['lastname'] == "") {
$row['firstname'] == "No Info";
}
var_dump($row['firstname']);
var_dump($row['lastname']);
echo '<tr>' . "\n";
echo '<td>'.$row['username'].'</td>' . "\n";
echo '<td>'.$row['firstname'].'</td>' . "\n";
echo '<td>'.$row['lastname'].'</td>' . "\n";
echo '</tr>' . "\n";
}
echo "</table>\n";
function getRowsByArticleSearch($searchString, $table) {
$con = mysqli_connect("localhost","user","password", "database");
$recordsQuery = "SELECT username, firstname, lastname FROM $table WHERE lower(username) LIKE ? ";
if ($getRecords = $con->prepare($recordsQuery)) {
$getRecords->bind_param("s", $searchString);
$getRecords->execute();
$getRecords->bind_result($username, $firstname, $lastname);
$rows = array();
while ($getRecords->fetch()) {
$row = array(
'username' => $username,
'firstname' => $firstname,
'lastname' => $lastname,
);
$rows[] = $row;
}
return $rows;
} else {
print_r($con->error);
}
}

Answer 1

Turn on display_errors and set error_reporting to E_ALL (either in php.ini or in a htaccess). This should reveal any non-obvious mistakes.
Try the following for checking if something is empty:
<?php
if(!isset($row['...']) || empty($row['...']))
{
$row['firstname'] = 'No Info';
}
?>
Also, please note you're using '==' to set the $row things to 'No Info'. Al this does is return 'true' (or 1). Use a single '=' to set variables.

Answer 2

First and your main issue:
You are using comparison operators in $row['firstname'] == "No Info"; instead of assignement operators $row['firstname'] = "No Info";
Other issues:
Why do you establish the connection twice? Or actually multiple times? Find a way to let your functions know the connection!
Factor the connection out into an include.
Why do you do that while loop, if you can access the returned array directly?

Answer 3

Two things to try...
if($row['field'] === NULL) { }
if(isset($row['field'])) { }

Answer 4

You can check the empty data using is_null property .Refer this link for more details
http://php.net/manual/en/function.is-null.php
is_null($row['field'])
Use
if(is_null($rows['field'])){
// Code Here
}else{
//code here
}