Database.Persist.PersistValue

This module contains an intermediate representation of values before the backends serialize them into explicit database types.

Since: 2.13.0.0

Documentation

data PersistValue

A raw value which can be stored in any backend and can be marshalled to and from a PersistField.

Constructors

PersistText Text

PersistByteString ByteString

PersistInt64 Int64

PersistDouble Double

PersistRational Rational

PersistBool Bool

PersistDay Day

PersistTimeOfDay TimeOfDay

PersistUTCTime UTCTime

PersistNull

PersistList [PersistValue]

PersistMap [(Text, PersistValue)]

PersistObjectId ByteString

Intended especially for MongoDB backend

PersistArray [PersistValue]

Intended especially for PostgreSQL backend for text arrays

PersistLiteral_ LiteralType ByteString

This constructor is used to specify some raw literal value for the backend. The LiteralType value specifies how the value should be escaped. This can be used to make special, custom types avaialable in the back end.

Since: 2.12.0.0

Bundled Patterns

pattern PersistLiteral :: ByteString -> PersistValue

This pattern synonym used to be a data constructor on PersistValue, but was changed into a catch-all pattern synonym to allow backwards compatiblity with database types. See the documentation on PersistDbSpecific for more details.

Since: 2.12.0.0

pattern PersistLiteralEscaped :: ByteString -> PersistValue

This pattern synonym used to be a data constructor on PersistValue, but was changed into a catch-all pattern synonym to allow backwards compatiblity with database types. See the documentation on PersistDbSpecific for more details.

Since: 2.12.0.0

pattern PersistDbSpecific :: ByteString -> PersistValue

Deprecated: Deprecated since 2.11 because of inconsistent escaping behavior across backends. The Postgres backend escapes these values, while the MySQL backend does not. If you are using this, please switch to PersistLiteral_ and provide a relevant LiteralType for your conversion.

This pattern synonym used to be a data constructor for the PersistValue type. It was changed to be a pattern so that JSON-encoded database values could be parsed into their corresponding values. You should not use this, and instead prefer to pattern match on PersistLiteral_ directly.

If you use this, it will overlap a patern match on the 'PersistLiteral_, PersistLiteral, and PersistLiteralEscaped patterns. If you need to disambiguate between these constructors, pattern match on PersistLiteral_ directly.

Since: 2.12.0.0

Instances

FromJSON PersistValue

Defined in Database.Persist.PersistValue

Methods

parseJSON :: Value -> Parser PersistValue

parseJSONList :: Value -> Parser [PersistValue]

ToJSON PersistValue

Defined in Database.Persist.PersistValue

Methods

toJSON :: PersistValue -> Value

toEncoding :: PersistValue -> Encoding

toJSONList :: [PersistValue] -> Value

toEncodingList :: [PersistValue] -> Encoding

Read PersistValue

Defined in Database.Persist.PersistValue

Methods

readsPrec :: Int -> ReadS PersistValue

readList :: ReadS [PersistValue]

readPrec :: ReadPrec PersistValue

readListPrec :: ReadPrec [PersistValue]

Show PersistValue

Defined in Database.Persist.PersistValue

Methods

showsPrec :: Int -> PersistValue -> ShowS

show :: PersistValue -> String

showList :: [PersistValue] -> ShowS

NFData PersistValue

Since: 2.14.4.0

Defined in Database.Persist.PersistValue

Methods

rnf :: PersistValue -> ()

Eq PersistValue

Defined in Database.Persist.PersistValue

Methods

(==) :: PersistValue -> PersistValue -> Bool

(/=) :: PersistValue -> PersistValue -> Bool

Ord PersistValue

Defined in Database.Persist.PersistValue

Methods

compare :: PersistValue -> PersistValue -> Ordering

(<) :: PersistValue -> PersistValue -> Bool

(<=) :: PersistValue -> PersistValue -> Bool

(>) :: PersistValue -> PersistValue -> Bool

(>=) :: PersistValue -> PersistValue -> Bool

max :: PersistValue -> PersistValue -> PersistValue

min :: PersistValue -> PersistValue -> PersistValue

FromHttpApiData PersistValue

Defined in Database.Persist.PersistValue

Methods

parseUrlPiece :: Text -> Either Text PersistValue

parseHeader :: ByteString -> Either Text PersistValue

parseQueryParam :: Text -> Either Text PersistValue

ToHttpApiData PersistValue

Defined in Database.Persist.PersistValue

Methods

toUrlPiece :: PersistValue -> Text

toEncodedUrlPiece :: PersistValue -> Builder

toHeader :: PersistValue -> ByteString

toQueryParam :: PersistValue -> Text

PathPiece PersistValue

Defined in Database.Persist.PersistValue

Methods

fromPathPiece :: Text -> Maybe PersistValue

toPathPiece :: PersistValue -> Text

PersistField PersistValue

Defined in Database.Persist.Class.PersistField

Methods

toPersistValue :: PersistValue -> PersistValue

fromPersistValue :: PersistValue -> Either Text PersistValue

PersistFieldSql PersistValue

Defined in Database.Persist.Sql.Class

Methods

sqlType :: Proxy PersistValue -> SqlType

fromPersistValueText :: PersistValue -> Either Text Text

data LiteralType

A type that determines how a backend should handle the literal.

Since: 2.12.0.0

Constructors

Escaped

The accompanying value will be escaped before inserting into the database. This is the correct default choice to use.

Since: 2.12.0.0

Unescaped

The accompanying value will not be escaped when inserting into the database. This is potentially dangerous - use this with care.

Since: 2.12.0.0

DbSpecific

The DbSpecific constructor corresponds to the legacy PersistDbSpecific constructor. We need to keep this around because old databases may have serialized JSON representations that reference this. We don't want to break the ability of a database to load rows.

Since: 2.12.0.0

Instances

Read LiteralType

Defined in Database.Persist.PersistValue

Methods

readsPrec :: Int -> ReadS LiteralType

readList :: ReadS [LiteralType]

readPrec :: ReadPrec LiteralType

readListPrec :: ReadPrec [LiteralType]

Show LiteralType

Defined in Database.Persist.PersistValue

Methods

showsPrec :: Int -> LiteralType -> ShowS

show :: LiteralType -> String

showList :: [LiteralType] -> ShowS

Eq LiteralType

Defined in Database.Persist.PersistValue

Methods

(==) :: LiteralType -> LiteralType -> Bool

(/=) :: LiteralType -> LiteralType -> Bool

Ord LiteralType

Defined in Database.Persist.PersistValue

Methods

compare :: LiteralType -> LiteralType -> Ordering

(<) :: LiteralType -> LiteralType -> Bool

(<=) :: LiteralType -> LiteralType -> Bool

(>) :: LiteralType -> LiteralType -> Bool

(>=) :: LiteralType -> LiteralType -> Bool

max :: LiteralType -> LiteralType -> LiteralType

min :: LiteralType -> LiteralType -> LiteralType