yesodweb/persistent
newtype interferes with unique constraints in MySQL
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#100 geöffnet am 29.10.2012
Feature RequestMySQLgood first issue
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Beschreibung
Text fields can have unique constraints over them.
However, when a Text field is newtype'd, for extra type safety, this facility appears to break:
In Model.hs with GeneralizedNewtypeDeriving:
newtype Hash = Hash { unHash :: Text }
deriving (Show, Read, Eq, PathPiece, PersistField)
In config/models:
Profile
hash Hash
UniqueHash hash
On initial database migration with mysql, we see:
Migrating: ALTER TABLE `profile` ADD CONSTRAINT `unique_hash` UNIQUE(`hash`)
hpd3js: ConnectionError {errFunction = "query", errNumber = 1170, errMessage = "BLOB/TEXT column 'hash' used in key specification without a key length"}
Uncaught instance of overlapping instances floating around, perhaps? (Am I missing a deriving statement?)