mongodb/doc/Example.hs
2014-07-07 09:05:03 +04:00

48 lines
1.8 KiB
Haskell

{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE ExtendedDefaultRules #-}
module Main (main) where
import Database.MongoDB (Action, Document, Document, Value, access,
close, connect, delete, exclude, find,
host, insertMany, master, project, rest,
select, sort, (=:))
import Control.Monad.Trans (liftIO)
main :: IO ()
main = do
pipe <- connect (host "127.0.0.1")
e <- access pipe master "baseball" run
close pipe
print e
run :: Action IO ()
run = do
clearTeams
insertTeams
allTeams >>= printDocs "All Teams"
nationalLeagueTeams >>= printDocs "National League Teams"
newYorkTeams >>= printDocs "New York Teams"
clearTeams :: Action IO ()
clearTeams = delete (select [] "team")
insertTeams :: Action IO [Value]
insertTeams = insertMany "team" [
["name" =: "Yankees", "home" =: ["city" =: "New York", "state" =: "NY"], "league" =: "American"],
["name" =: "Mets", "home" =: ["city" =: "New York", "state" =: "NY"], "league" =: "National"],
["name" =: "Phillies", "home" =: ["city" =: "Philadelphia", "state" =: "PA"], "league" =: "National"],
["name" =: "Red Sox", "home" =: ["city" =: "Boston", "state" =: "MA"], "league" =: "American"] ]
allTeams :: Action IO [Document]
allTeams = rest =<< find (select [] "team") {sort = ["home.city" =: 1]}
nationalLeagueTeams :: Action IO [Document]
nationalLeagueTeams = rest =<< find (select ["league" =: "National"] "team")
newYorkTeams :: Action IO [Document]
newYorkTeams = rest =<< find (select ["home.state" =: "NY"] "team") {project = ["name" =: 1, "league" =: 1]}
printDocs :: String -> [Document] -> Action IO ()
printDocs title docs = liftIO $ putStrLn title >> mapM_ (print . exclude ["_id"]) docs