BookingID PHP Script

OTHER_INFORMATION/php files/bookingIDCheck.php

+<?php
+
+if(isset($_POST['bookingID'])){
+
+    $bookingID = htmlspecialchars($_POST['bookingID']);
+    while(true){
+   
+    require_once "connect_db.php";
+
+    $sql = 'SELECT * FROM receipt_museum WHERE bookingID= ?;';
+
+    $stmt = mysqli_stmt_init($connect);
+
+    if (!mysqli_stmt_prepare($stmt, $sql)) {
+        echo  'failure';
+    } else {
+
+        mysqli_stmt_bind_param($stmt, "i", $bookingID);
+        mysqli_stmt_execute($stmt);
+
+        $result = mysqli_stmt_get_result($stmt);
+
+        if (mysqli_fetch_assoc($result)) {
+            $bookingID = mt_rand(100000,999999); 
+        } 
+        else {
+            break;
+        }
+    }
+   
+    
+}
+mysqli_stmt_close($stmt);
+echo $bookingID;
+} else{
+    echo 'no submit';
+}
\ No newline at end of file