[Haskell-beginners] (SPAM 3)Re: monad and variable result

[Francesco Ariis]

On Mon, Dec 10, 2018 at 03:46:46PM +0100, Damien Mattei wrote:
> query returns a list i suppose because i can wirte this in my main code:
>  bd_rows <- query conn qry_head (Only (name::String))

`query` does not return a `[r]`, rather an `IO [r]`. The difference
is very important; if you don't get it you will always have troubles
with Haskell. This will for sure help you

    https://www.seas.upenn.edu/~cis194/fall16/lectures/06-io-and-monads.html