For insert (Create), one can do:
$params = array(
'A new post',
'detachedsoul',
'This would be the dummy content of this post'
);
$insert = DB::getInstance()->insert('post', ['title', 'author', 'content'], ...$params);
For select (Read), one can do:
$author = "detachedsoul";
$select = DB::getInstance()->select('*', 'posts', 'WHERE author = ?', $author);
OR
$select = DB::getInstance()->select('*', 'posts');
For update (Update), one can do:
$params = [
'Title has changed',
'detachedsoul'
];
$update = DB::getInstance()->update('post', 'title = ?', 'WHERE author = ?', ...$params);
For delete (Delete), one can do:
$id = 2;
$delete = DB::getInstance()->delete('post', 'id', $id);