我在Docker容器中的服务器上有Postgresql.如何从外部(即从我的本地计算机)连接到它?我应该采用什么设置才能允许?
我正在导入这个:
import Data.Aeson (ToJSON(..), FromJSON(..), (.:), (.=), object, Object(..), decode)
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我有这个:
instance FromJSON Data123 where
parseJSON (Object v) =
Data123 <$> v .: "a"
<*> v .: "b"
<*> v .: "c"
parseJSON _ = mzero
instance ToJSON Data123 where
toJSON (Data123 a b c) =
object ["a" .= a
, "b" .= b
, "c" .= c
]
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我有一个错误说
Not in scope: data constructor ‘Object’
Perhaps you meant variable ‘object’ (imported from Data.Aeson)
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我还没有进口吗?