Selda Crash

Main.hs

{-# LANGUAGE DeriveGeneric #-}
{-# LANGUAGE OverloadedLabels #-}
{-# LANGUAGE OverloadedStrings #-}

module Main where

import Database.Selda
import Database.Selda.SQLite

data Person
  = Person
      { name :: Text,
        age :: Int
      }
  deriving (Generic)

instance SqlRow Person

people :: Table Person
people = table "people" [#name :- primary]

data Pet
  = Pet
      { petname :: Text,
        owner :: Text
      }
  deriving (Generic, Show)

instance SqlRow Pet

pets :: Table Pet
pets = table "pets" [#petname :- primary]

main = withSQLite "people.sqlite" $ do
  createTable people
  insert_
    people
    [ Person "Velvet" 19,
      Person "Kobayashi" 23,
      Person "Miyu" 10
    ]
  createTable pets
  insert_
    pets
    [ Pet "Fluffy" "Miyu"
    ]
  petsWithOwner <- query $ do
    person <- select people
    pet <- leftJoin (\p -> p ! #owner .== person ! #name) $ select pets
    return (pet :*: person ! #name)
  liftIO $ print petsWithOwner