PHP Single Image Upload REST API

upload.php

<?php
// Include the database configuration file
include '/server/connection.php';

if(is_uploaded_file($_FILES['file']['tmp_name'])){
    
    // File upload path
    $targetDir = "../uploads/";

    $file=$_FILES['file']['tmp_name'];
    $fileName = time()."-".$_FILES['file']['name'];

    $targetFilePath = $targetDir . $fileName;
    
    $fileType = pathinfo($targetFilePath,PATHINFO_EXTENSION);
    $allowTypes = array('jpg','png','jpeg'); // allowed image extensions
    
    //checking extensions
    if(in_array($fileType, $allowTypes)){
        // Upload file to server
        if(move_uploaded_file($_FILES["file"]["tmp_name"], $targetFilePath)){
            $query= $db->query($checkstmt); // $checkstmt refers to db query statement, executing query statement
            if($query){
                if($query){
                    echo json_encode(array("success_message" => "File has been uploaded successfully"));
                }else{
                    echo json_encode(array("error_message" => "File upload failed, please try again."));
                }  
            }

        }else{
            echo json_encode(array("error_message" => "Sorry, there was an error uploading your file."));
        }
    }else{
        echo json_encode(array("error_message" => "Sorry, only JPG, JPEG, PNG files are allowed to upload"));
    }
    
}else{
    echo json_encode(array("error_message" => "Data incomplete"));
}

?>