Select rows with some property

You can use all operators of type
Expr a -> Expr a -> Expr Bool
in your restrict, like for example
.==. ./=. .&&.
This example selects all farmers on the farm with farm_id 0

restr =
    withDB $ \db ->
    do rows <- query db $
               do result <- table P.farmers
                  restrict (result!P.farm_id .==. constant 0)
                  return result
       mapM_ (putStrLn .showP) rows


Frame> restr
    0 "John Doe" 0
    1 "Jane Doe" 0

Here are all words and functions with references, in alphabetical order

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