[Haskell-beginners] database access,extracting result...

3 Dec 2018

      {-# LANGUAGE OverloadedStrings #-}

import Database.MySQL.Simple
import Control.Monad
import Data.Text as Text
import Data.Int

main :: IO ()
main = do
  conn <- connect defaultConnectInfo
    { connectHost = "moita",
      connectUser = "mattei",
      connectPassword = "******",
      connectDatabase = "sidonie" }

  rows <- query_ conn "select `N° BD` from sidonie.Coordonnées where Nom
= 'A    20'"

  --putStrLn $ show rows

  forM_ rows $ \(fname, lname) ->
     putStrLn $  fname ++ " " ++ Text.unpack lname ++ " "

here is the error:

*Main> :load Toto
[1 of 1] Compiling Main             ( Toto.hs, interpreted )
Ok, one module loaded.
*Main> main
*** Exception: ConversionFailed {errSQLType = "1 values:
[(VarString,Just \"-04.3982\")]", errHaskellType = "2 slots in target
type", errFieldName = "[\"N\\194\\176 BD\"]", errMessage = "mismatch
between number of columns to convert and number in target type"}

-04.3982 is the values i want to put in a variable,it's the N° BD
(Durchmusterung Number)

???

any help greatly appeciated ;-)

-- 
Damien.Mattei@unice.fr, Damien.Mattei@oca.eu, UNS / OCA / CNRS

[Haskell-beginners] database access,extracting result...

Damien Mattei