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我有一个Haskell Status
类型:映射哈斯克尔类型Postgres数据库持久性
data Status = FirstViewed | Reviewed | Learned
我怎么能这个数据映射到持久Postgres数据库?
share [mkPersist sqlSettings, mkMigrate "migrateAll"] [persistLowerCase|
Vocabulary sql=vocabulary
word Text
date UTCTime
status Status
deriving Show
|]
你可以使用['derivePersistField'](https://hackage.haskell.org/package/persistent-template-2.5.2/docs/Database-Persist-TH.html#v:derivePersistField)模板Haskell函数为持久化派生必要的实例来序列化和反序列化它。 –