Вопрос

I'm getting a type error with a query right from the hackage page.
The query is supposed to select a GolfCourse whose name is equal to "Miniota".
Query:

getTestR :: Handler Html
getTestR = do
  gcs <- runDB $
          E.select $
          E.from $ \g -> do
          E.where_ (g E.^. GolfCourseName ==. E.val "Miniota")
          return g
  defaultLayout $(widgetFile "test")

The error:

Handler/Home.hs:713:49:
    Couldn't match expected type `Text' with actual type `E.Value typ0'
    Expected type: E.Value Text
      Actual type: E.Value (E.Value typ0)
    In the return type of a call of `E.val'
    In the second argument of `(==.)', namely `E.val "Miniota"'

I suspect that the error has to do with me incorrectly using E.val
I'm not actually using gcs in the widgetFile right now. Help would be very appreciated.

Это было полезно?

Решение

I'm not certain, but it might be that you need to use:

... E.==. E.val ...

Since the exact problem depends on your import statements, it's probably a good idea to provide a link to a complete, standalone file demonstrating the problem.

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