How to get database information from Joomla category

Question

I know how I can retrieve all information from a article in the database. I am trying to do the same thing for a category. And just for clarification, I am talking about when view is equal to category (index.php?option=com_content&view=category). Below is how I can retrieve any information for a article, when I am on a article page, I want to do the same exact thing, but when I am on a category page. Thanks!

$input = JFactory::getApplication()->input;
$articleId = $input->getInt('id');
$article = JTable::getInstance('content');
$article->load($articleId);
$articleTitle = $article->get('title');

Answer 1

All I had to do was change content to category and I was able to access all data within the category table using the same method I did with the content.

$input = JFactory::getApplication()->input;
$catId = $input->getInt('id');
$cat = JTable::getInstance('category');
$cat->load($catId);

Answer 2

When you are on a category view (view=category), You can simply retrieve the current category information as follows

$this->category->id;
$this->category->title;
$this->category->alias;
$this->category->description;

Answer 3

Try to add this function in your PHP file

function getCategory($id) {
    $app      = JFactory::getApplication();
    $database = JFactory::getDBO();
    $jinput   = $app->input;
    if (($jinput->get('view') == "category") || ($jinput->get('view') == "categories")) {
        return $id;
    } elseif ($jinput->get('view') == "article") {
        $sql  = "SELECT catid FROM #__content WHERE id = " . $id;
        $database->setQuery($sql);

        return $database->loadResult();
    }
}

$catId = getCategory($jinput->get('id', '', 'INT'));