[tel]

Some pseudocode

    playlistCount :: PromiseDB Int
    playlistCount = withConn $ \conn -> do
                      result <- query 'SELECT COUNT(id) AS count FROM Playlists;' conn
                      return (parseInt $ get 'count' result)

Wrapping the pool handling into withConn, and the failure modes into query. This PromiseDB monad would be fairly trivial to produce in Haskell. It's also fairly easy to write it point-free as

    withConn $ 
      query 'SELECT COUNT(id) AS count FROM Playlists;' 
      >=> return . parseInt . get 'count'