How to loop the query in this case? - php

Question

I have been trying to loop this query but all I get is the first value.
When I do the same command in workbench I get all the values.
What am I doing wrong here? Any answers are much appreciated!
global $db;
$stmt12 = $db->query('SELECT `Value` FROM overriddenpropertyvalues WHERE ParentGUID LIKE "' . $itemguid . '";');
$propertyvaluerow = $stmt12->fetch();
while ($propertyvaluerow != null) {

Answer 1

You are fetching only one value with ->fetch(). That's why you receive only one value.
Example from here:
$query = $db->prepare('SELECT `Value` FROM `overriddenpropertyvalues` WHERE ParentGUID LIKE :like');
$query->execute([':like' => $itemguid]);
$stmt->bind_result($value);
while ($query->fetch()) {
echo $value."<br/>"
}

Answer 2

There might possibly be a loophole in your Program depending on what the $stmt12->fetch() does. If it fetches an Array of Data, your while loop might not behave as expected. Below is a commented alternative to what you might want to try out:
<?php
global $db;
$stmt12 = $db->query('SELECT `Value` FROM overriddenpropertyvalues WHERE ParentGUID LIKE "' . $itemguid . '";');
// ASSUMES YOU ARE USING PDO SO WE FETCH ALL THE DATA
$propertyvaluerow = $stmt12->fetchAll();
// THERE MIGHT BE A LOOPHOLE IN YOUR PROGRAM DEPENDING ON WHAT $stmt12->fetch() IS AND DOES
// ASSUMING IT FETCHES AN ARRAY OF NESTED OBJECTS OR SCALAR VALUES, THE WHILE LOOP WOULD NOT BEHAVE AS EXPECTED.
// THAT MEANS IF IT IS AN ARRAY YOU COULD USE A DIFFERENT CONSTRUCT LIKE THE ONE BELOW YOUR WHILE CONSTRUCT:
/* while ($propertyvaluerow != null) { */
// CREATE A $count VARIABLE TO HOLD THE INCREMENTAL COUNT THROUGH THE ITERATION:
$count = count($propertyvaluerow);
while($count > 0){
// DO YOUR WORK HERE
//DECREMENT THE VALUE OF COUNT OTHERWISE YOU MAY HAVE AN INFINITE LOOP TO DEAL WITH.
$count--;
}
?>
There is yet another alternative:
<?php
// OR EVEN A MUCH MORE EASIER WAY IS TO USE THE FOREACH LOOP, WHICH ACHIEVES THE SAME THING AS THE WHILE LOOP:
foreach($propertyvaluerow as $iKey=>$objData){
// SIMPLY USE THE $objData IN WITHING THE LOOP
// THE $objData IS THE VALUE OF THE CURRENT OBJECT IN THE $propertyvaluerow IN THE ITERATION
}

Answer 3

Best way:
global $db;
$stmt = $db->prepare('SELECT `Value` FROM OverriddenPropertyValues WHERE ParentGUID=?');
$stmt->execute([$itemguid]);
$rows = $stmt->fetchAll();
foreach($rows as $row) {
// $row->Value or $row['Value']
}