how to upload multiple images using Longblob

if (count($_FILES) > 0) {

    if (is_uploaded_file($_FILES['userImage']['tmp_name'])) {

        $imgData = addslashes(file_get_contents($_FILES['userImage']['tmp_name']));
        $imageProperties = getimageSize($_FILES['userImage']['tmp_name']);

        $sql = "INSERT INTO trial (imageType ,imageData,uploaded_on, user_id,tax_payer_id)
                VALUES('{$imageProperties['mime']}', '{$imgData}',NOW(),'".$_SESSION['id']."','".$_GET['id']."')";
        $current_id =  mysqli_query($db, $sql) or die("<b>Error:</b> Problem on Image Insert<br/>" . mysqli_error($db));
        $current_id = mysqli_insert_id($db);

        if (isset($current_id)) {
           echo "Upload Succesfully";
        }else{
            echo "There is a problem";
        }
    }
}
?>  

    <form name="frmImage" enctype="multipart/form-data" action="" method="post"                         class="frmImageUpload">
        <label>Upload QrCode File:</label><br /> 
        <input type="file" class="inputFile" name="userImage" />
                <input type="hidden" name="imageID"  value="<?php if(!empty($_GET['id'])){ echo $_GET['id'];} ?>">
        <input type="submit" value="Submit" class="btnSubmit" />
    </form>

I'm trying to upload multiple images and I'm using longblob to store the images in database.