Finding the MAX id of a table and inputting elsewhere - php

Question

So I'm trying to get the max id of a table which I can do using
SELECT * FROM forsale ORDER BY StockID DESC LIMIT 0,1
I then save the result so I can use it in another table for reference when displaying images. The only issue is when I print the result it shows the MAX id but no inputting it into the table? Does anyone have an suggestions? I have code prior to this inputting into the forsale table and I am then getting the ID of that record. Here's what I get in the table, here's the code:
if(isset($_POST['add'])){
include '../Login-System/db.php';
$make = mysqli_real_escape_string($conn, $_POST['Make']);
$model = mysqli_real_escape_string($conn, $_POST['Model']);
$variant = mysqli_real_escape_string($conn, $_POST['Variant']);
$year = mysqli_real_escape_string($conn, $_POST['Year']);
$mileage = mysqli_real_escape_string($conn, $_POST['Mileage']);
$fuel = mysqli_real_escape_string($conn, $_POST['Fuel']);
$doors = mysqli_real_escape_string($conn, $_POST['Doors']);
$trans = mysqli_real_escape_string($conn, $_POST['transmission']);
$enginesize = mysqli_real_escape_string($conn, $_POST['Enginesize']);
$price = mysqli_real_escape_string($conn, $_POST['Price']);
$description = mysqli_real_escape_string($conn, $_POST['description']);
$makeupper = strtoupper($make);
$modelupper =strtoupper($model);
$variantupper =strtoupper($variant);
$sqlcarinsert = "INSERT INTO forsale (make, model, variant, year, mileage, fuel, doors, trans, enginesize, price, description) VALUES ('$makeupper','$modelupper','$variantupper','$year','$mileage','$fuel','$doors','$trans','$enginesize','$price','$description');";
//Image Upload
//Find next StockID
$sql = "SELECT * FROM forsale ORDER BY StockID DESC LIMIT 0, 1";
$result = mysqli_query($conn, $sql);
$stockIDtable = mysqli_fetch_assoc($result);
$stockID = $stockIDtable['StockID'];
if(!empty($_FILES['files']['name'][0])){
$files = $_FILES['files'];
//File Extensions allowed
$allowed = array('jpg', 'jpeg', 'png');
foreach ($files['name'] as $position => $file_name) {
$file_tmp = $files['tmp_name'] [$position];
$file_size = $files['size'] [$position];
$file_error = $files['error'] [$position];
//Order
$orderimg = $position;
//Get file extension
$FileExt = explode('.', $file_name);
$endext = end($FileExt);
$fileActualExt = strtolower($endext);
if (in_array($fileActualExt, $allowed)) {
//Checks for Errors in uploading
if ($file_error === 0) {
//New name to remove possibilities of duplicates
$fileNameNew = uniqid('', true).".".$fileActualExt ;
$FileDestination = '../Photos/forsale/'.$fileNameNew;
$SQLDestination = 'Photos/forsale/'.$fileNameNew;
//Upload to Designated folder with name
move_uploaded_file($file_tmp, $FileDestination);
//Insert into forsaleimg
$sqlimginsert = "INSERT INTO forsaleimg (id, StockID, imgOrder, FileDestination) VALUES ('NULL', '$stockID', '$orderimg', '$SQLDestination');";
mysqli_query($conn, $sqlimginsert);
//echo "<pre>";
//print_r($sqlimginsert);
//echo "</pre>";
$orderimg++ ;
} else {
header("Location: ../salelist.php?upload=error");
exit();
}
} else {
header("Location: ../salelist.php?fucked");
exit();
}
}
}
mysqli_query($conn, $sqlcarinsert);
header("Location: ../salelist.php?added=".$make);
exit();
} else {
header("Location: ../salelist.php?add=notclicked");
exit();
}

Answer 1

Use the query as:-
$sql = "select * from forsale
where StockID = (select max(StockID) as 'StockID'
from forsale)
order by StockID" ;