Database.Persist.Types

Documentation

data Checkmark

A Checkmark should be used as a field type whenever a uniqueness constraint should guarantee that a certain kind of record may appear at most once, but other kinds of records may appear any number of times.

NOTE: You need to mark any Checkmark fields as nullable (see the following example).

For example, suppose there's a Location entity that represents where a user has lived:

Location
    user    UserId
    name    Text
    current Checkmark nullable

    UniqueLocation user current

The UniqueLocation constraint allows any number of Inactive Locations to be current. However, there may be at most one current Location per user (i.e., either zero or one per user).

This data type works because of the way that SQL treats NULLable fields within uniqueness constraints. The SQL standard says that NULL values should be considered different, so we represent Inactive as SQL NULL, thus allowing any number of Inactive records. On the other hand, we represent Active as TRUE, so the uniqueness constraint will disallow more than one Active record.

Note: There may be DBMSs that do not respect the SQL standard's treatment of NULL values on uniqueness constraints, please check if this data type works before relying on it.

The SQL BOOLEAN type is used because it's the smallest data type available. Note that we never use FALSE, just TRUE and NULL. Provides the same behavior Maybe () would if () was a valid PersistField.

Constructors

Active

When used on a uniqueness constraint, there may be at most one Active record.

Inactive

When used on a uniqueness constraint, there may be any number of Inactive records.

Instances

Bounded Checkmark

Defined in Database.Persist.Types.Base

Methods

minBound :: Checkmark

maxBound :: Checkmark

Enum Checkmark

Defined in Database.Persist.Types.Base

Methods

succ :: Checkmark -> Checkmark

pred :: Checkmark -> Checkmark

toEnum :: Int -> Checkmark

fromEnum :: Checkmark -> Int

enumFrom :: Checkmark -> [Checkmark]

enumFromThen :: Checkmark -> Checkmark -> [Checkmark]

enumFromTo :: Checkmark -> Checkmark -> [Checkmark]

enumFromThenTo :: Checkmark -> Checkmark -> Checkmark -> [Checkmark]

Eq Checkmark

Defined in Database.Persist.Types.Base

Methods

(==) :: Checkmark -> Checkmark -> Bool

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

Ord Checkmark

Defined in Database.Persist.Types.Base

Methods

compare :: Checkmark -> Checkmark -> Ordering

(<) :: Checkmark -> Checkmark -> Bool

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

(>) :: Checkmark -> Checkmark -> Bool

(>=) :: Checkmark -> Checkmark -> Bool

max :: Checkmark -> Checkmark -> Checkmark

min :: Checkmark -> Checkmark -> Checkmark

Read Checkmark

Defined in Database.Persist.Types.Base

Methods

readsPrec :: Int -> ReadS Checkmark

readList :: ReadS [Checkmark]

readPrec :: ReadPrec Checkmark

readListPrec :: ReadPrec [Checkmark]

Show Checkmark

Defined in Database.Persist.Types.Base

Methods

showsPrec :: Int -> Checkmark -> ShowS

show :: Checkmark -> String

showList :: [Checkmark] -> ShowS

ToHttpApiData Checkmark

Defined in Database.Persist.Types.Base

Methods

toUrlPiece :: Checkmark -> Text

toEncodedUrlPiece :: Checkmark -> Builder

toHeader :: Checkmark -> ByteString

toQueryParam :: Checkmark -> Text

FromHttpApiData Checkmark

Defined in Database.Persist.Types.Base

Methods

parseUrlPiece :: Text -> Either Text Checkmark

parseHeader :: ByteString -> Either Text Checkmark

parseQueryParam :: Text -> Either Text Checkmark

PathPiece Checkmark

Defined in Database.Persist.Types.Base

Methods

fromPathPiece :: Text -> Maybe Checkmark

toPathPiece :: Checkmark -> Text

PersistField Checkmark

Defined in Database.Persist.Class.PersistField

Methods

toPersistValue :: Checkmark -> PersistValue

fromPersistValue :: PersistValue -> Either Text Checkmark

PersistFieldSql Checkmark

Defined in Database.Persist.Sql.Class

Methods

sqlType :: Proxy Checkmark -> SqlType

data IsNullable

Constructors

Nullable !WhyNullable

NotNullable

Instances

Eq IsNullable

Defined in Database.Persist.Types.Base

Methods

(==) :: IsNullable -> IsNullable -> Bool

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

Show IsNullable

Defined in Database.Persist.Types.Base

Methods

showsPrec :: Int -> IsNullable -> ShowS

show :: IsNullable -> String

showList :: [IsNullable] -> ShowS

data WhyNullable

The reason why a field is nullable is very important. A field that is nullable because of a Maybe tag will have its type changed from A to Maybe A. OTOH, a field that is nullable because of a nullable tag will remain with the same type.

Constructors

ByMaybeAttr

ByNullableAttr

Instances

Eq WhyNullable

Defined in Database.Persist.Types.Base

Methods

(==) :: WhyNullable -> WhyNullable -> Bool

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

Show WhyNullable

Defined in Database.Persist.Types.Base

Methods

showsPrec :: Int -> WhyNullable -> ShowS

show :: WhyNullable -> String

showList :: [WhyNullable] -> ShowS

data EntityDef

An EntityDef represents the information that persistent knows about an Entity. It uses this information to generate the Haskell datatype, the SQL migrations, and other relevant conversions.

Constructors

EntityDef

Fields

• entityHaskell :: !HaskellName

  The name of the entity as Haskell understands it.

• entityDB :: !DBName

  The name of the database table corresponding to the entity.

• entityId :: !FieldDef

  The entity's primary key or identifier.

• entityAttrs :: ![Attr]

  The persistent entity syntax allows you to add arbitrary Attrs to an entity using the ! operator. Those attributes are stored in this list.

• entityFields :: ![FieldDef]

  The fields for this entity. Note that the ID field will not be present in this list. To get all of the fields for an entity, use keyAndEntityFields.

• entityUniques :: ![UniqueDef]

  The Uniqueness constraints for this entity.

• entityForeigns :: ![ForeignDef]

  The foreign key relationships that this entity has to other entities.

• entityDerives :: ![Text]

  A list of type classes that have been derived for this entity.

• entityExtra :: !(Map Text [ExtraLine])
• entitySum :: !Bool

  Whether or not this entity represents a sum type in the database.

• entityComments :: !(Maybe Text)

  Optional comments on the entity.

  Since: 2.10.0

Instances

Eq EntityDef

Defined in Database.Persist.Types.Base

Methods

(==) :: EntityDef -> EntityDef -> Bool

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

Ord EntityDef

Defined in Database.Persist.Types.Base

Methods

compare :: EntityDef -> EntityDef -> Ordering

(<) :: EntityDef -> EntityDef -> Bool

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

(>) :: EntityDef -> EntityDef -> Bool

(>=) :: EntityDef -> EntityDef -> Bool

max :: EntityDef -> EntityDef -> EntityDef

min :: EntityDef -> EntityDef -> EntityDef

Read EntityDef

Defined in Database.Persist.Types.Base

Methods

readsPrec :: Int -> ReadS EntityDef

readList :: ReadS [EntityDef]

readPrec :: ReadPrec EntityDef

readListPrec :: ReadPrec [EntityDef]

Show EntityDef

Defined in Database.Persist.Types.Base

Methods

showsPrec :: Int -> EntityDef -> ShowS

show :: EntityDef -> String

showList :: [EntityDef] -> ShowS

entitiesPrimary :: EntityDef -> Maybe [FieldDef]

entityPrimary :: EntityDef -> Maybe CompositeDef

entityKeyFields :: EntityDef -> [FieldDef]

keyAndEntityFields :: EntityDef -> [FieldDef]

type ExtraLine = [Text]

newtype HaskellName

Constructors

HaskellName

Fields

• unHaskellName :: Text

Instances

Eq HaskellName

Defined in Database.Persist.Types.Base

Methods

(==) :: HaskellName -> HaskellName -> Bool

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

Ord HaskellName

Defined in Database.Persist.Types.Base

Methods

compare :: HaskellName -> HaskellName -> Ordering

(<) :: HaskellName -> HaskellName -> Bool

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

(>) :: HaskellName -> HaskellName -> Bool

(>=) :: HaskellName -> HaskellName -> Bool

max :: HaskellName -> HaskellName -> HaskellName

min :: HaskellName -> HaskellName -> HaskellName

Read HaskellName

Defined in Database.Persist.Types.Base

Methods

readsPrec :: Int -> ReadS HaskellName

readList :: ReadS [HaskellName]

readPrec :: ReadPrec HaskellName

readListPrec :: ReadPrec [HaskellName]

Show HaskellName

Defined in Database.Persist.Types.Base

Methods

showsPrec :: Int -> HaskellName -> ShowS

show :: HaskellName -> String

showList :: [HaskellName] -> ShowS

newtype DBName

Constructors

DBName

Fields

• unDBName :: Text

Instances

Eq DBName

Defined in Database.Persist.Types.Base

Methods

(==) :: DBName -> DBName -> Bool

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

Ord DBName

Defined in Database.Persist.Types.Base

Methods

compare :: DBName -> DBName -> Ordering

(<) :: DBName -> DBName -> Bool

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

(>) :: DBName -> DBName -> Bool

(>=) :: DBName -> DBName -> Bool

max :: DBName -> DBName -> DBName

min :: DBName -> DBName -> DBName

Read DBName

Defined in Database.Persist.Types.Base

Methods

readsPrec :: Int -> ReadS DBName

readList :: ReadS [DBName]

readPrec :: ReadPrec DBName

readListPrec :: ReadPrec [DBName]

Show DBName

Defined in Database.Persist.Types.Base

Methods

showsPrec :: Int -> DBName -> ShowS

show :: DBName -> String

showList :: [DBName] -> ShowS

type Attr = Text

data FieldAttr

Attributes that may be attached to fields that can affect migrations and serialization in backend-specific ways.

While we endeavor to, we can't forsee all use cases for all backends, and so FieldAttr is extensible through its constructor FieldAttrOther.

Since: 2.11.0.0

Constructors

FieldAttrMaybe

FieldAttrNullable

FieldAttrMigrationOnly

FieldAttrSafeToRemove

FieldAttrNoreference

FieldAttrReference Text

FieldAttrConstraint Text

FieldAttrDefault Text

FieldAttrSqltype Text

FieldAttrMaxlen Integer

FieldAttrOther Text

Instances

Eq FieldAttr

Defined in Database.Persist.Types.Base

Methods

(==) :: FieldAttr -> FieldAttr -> Bool

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

Ord FieldAttr

Defined in Database.Persist.Types.Base

Methods

compare :: FieldAttr -> FieldAttr -> Ordering

(<) :: FieldAttr -> FieldAttr -> Bool

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

(>) :: FieldAttr -> FieldAttr -> Bool

(>=) :: FieldAttr -> FieldAttr -> Bool

max :: FieldAttr -> FieldAttr -> FieldAttr

min :: FieldAttr -> FieldAttr -> FieldAttr

Read FieldAttr

Defined in Database.Persist.Types.Base

Methods

readsPrec :: Int -> ReadS FieldAttr

readList :: ReadS [FieldAttr]

readPrec :: ReadPrec FieldAttr

readListPrec :: ReadPrec [FieldAttr]

Show FieldAttr

Defined in Database.Persist.Types.Base

Methods

showsPrec :: Int -> FieldAttr -> ShowS

show :: FieldAttr -> String

showList :: [FieldAttr] -> ShowS

parseFieldAttrs :: [Text] -> [FieldAttr]

Parse raw field attributes into structured form. Any unrecognized attributes will be preserved, identically as they are encountered, as FieldAttrOther values.

Since: 2.11.0.0

data FieldType

A FieldType describes a field parsed from the QuasiQuoter and is used to determine the Haskell type in the generated code.

name Text parses into FTTypeCon Nothing Text

name T.Text parses into FTTypeCon (Just T Text)

name (Jsonb User) parses into:

FTApp (FTTypeCon Nothing Jsonb) (FTTypeCon Nothing User)

Constructors

FTTypeCon (Maybe Text) Text

Optional module and name.

FTApp FieldType FieldType

FTList FieldType

Instances

Eq FieldType

Defined in Database.Persist.Types.Base

Methods

(==) :: FieldType -> FieldType -> Bool

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

Ord FieldType

Defined in Database.Persist.Types.Base

Methods

compare :: FieldType -> FieldType -> Ordering

(<) :: FieldType -> FieldType -> Bool

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

(>) :: FieldType -> FieldType -> Bool

(>=) :: FieldType -> FieldType -> Bool

max :: FieldType -> FieldType -> FieldType

min :: FieldType -> FieldType -> FieldType

Read FieldType

Defined in Database.Persist.Types.Base

Methods

readsPrec :: Int -> ReadS FieldType

readList :: ReadS [FieldType]

readPrec :: ReadPrec FieldType

readListPrec :: ReadPrec [FieldType]

Show FieldType

Defined in Database.Persist.Types.Base

Methods

showsPrec :: Int -> FieldType -> ShowS

show :: FieldType -> String

showList :: [FieldType] -> ShowS

data FieldDef

A FieldDef represents the information that persistent knows about a field of a datatype. This includes information used to parse the field out of the database and what the field corresponds to.

Constructors

FieldDef

Fields

• fieldHaskell :: !HaskellName

  The name of the field. Note that this does not corresponds to the record labels generated for the particular entity - record labels are generated with the type name prefixed to the field, so a FieldDef that contains a HaskellName "name" for a type User will have a record field userName.

• fieldDB :: !DBName

  The name of the field in the database. For SQL databases, this corresponds to the column name.

• fieldType :: !FieldType

  The type of the field in Haskell.

• fieldSqlType :: !SqlType

  The type of the field in a SQL database.

• fieldAttrs :: ![FieldAttr]

  Whether or not the field is gnerated and how. Backend-dependent. ^ User annotations for a field. These are provided with the ! operator.

• fieldStrict :: !Bool

  If this is True, then the Haskell datatype will have a strict record field. The default value for this is True.

• fieldReference :: !ReferenceDef
• fieldCascade :: !FieldCascade

  Defines how operations on the field cascade on to the referenced tables. This doesn't have any meaning if the fieldReference is set to NoReference or SelfReference. The cascade option here should be the same as the one obtained in the fieldReference.

  Since: 2.11.0

• fieldComments :: !(Maybe Text)

  Optional comments for a Field. There is not currently a way to attach comments to a field in the quasiquoter.

  Since: 2.10.0

• fieldGenerated :: !(Maybe Text)

  Whether or not the field is a GENERATED column, and additionally the expression to use for generation.

  Since: 2.11.0.0

Instances

Eq FieldDef

Defined in Database.Persist.Types.Base

Methods

(==) :: FieldDef -> FieldDef -> Bool

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

Ord FieldDef

Defined in Database.Persist.Types.Base

Methods

compare :: FieldDef -> FieldDef -> Ordering

(<) :: FieldDef -> FieldDef -> Bool

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

(>) :: FieldDef -> FieldDef -> Bool

(>=) :: FieldDef -> FieldDef -> Bool

max :: FieldDef -> FieldDef -> FieldDef

min :: FieldDef -> FieldDef -> FieldDef

Read FieldDef

Defined in Database.Persist.Types.Base

Methods

readsPrec :: Int -> ReadS FieldDef

readList :: ReadS [FieldDef]

readPrec :: ReadPrec FieldDef

readListPrec :: ReadPrec [FieldDef]

Show FieldDef

Defined in Database.Persist.Types.Base

Methods

showsPrec :: Int -> FieldDef -> ShowS

show :: FieldDef -> String

showList :: [FieldDef] -> ShowS

isFieldNotGenerated :: FieldDef -> Bool

data ReferenceDef

There are 3 kinds of references 1) composite (to fields that exist in the record) 2) single field 3) embedded

Constructors

NoReference

ForeignRef !HaskellName !FieldType

A ForeignRef has a late binding to the EntityDef it references via HaskellName and has the Haskell type of the foreign key in the form of FieldType

EmbedRef EmbedEntityDef

CompositeRef CompositeDef

SelfReference

A SelfReference stops an immediate cycle which causes non-termination at compile-time (issue #311).

Instances

Eq ReferenceDef

Defined in Database.Persist.Types.Base

Methods

(==) :: ReferenceDef -> ReferenceDef -> Bool

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

Ord ReferenceDef

Defined in Database.Persist.Types.Base

Methods

compare :: ReferenceDef -> ReferenceDef -> Ordering

(<) :: ReferenceDef -> ReferenceDef -> Bool

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

(>) :: ReferenceDef -> ReferenceDef -> Bool

(>=) :: ReferenceDef -> ReferenceDef -> Bool

max :: ReferenceDef -> ReferenceDef -> ReferenceDef

min :: ReferenceDef -> ReferenceDef -> ReferenceDef

Read ReferenceDef

Defined in Database.Persist.Types.Base

Methods

readsPrec :: Int -> ReadS ReferenceDef

readList :: ReadS [ReferenceDef]

readPrec :: ReadPrec ReferenceDef

readListPrec :: ReadPrec [ReferenceDef]

Show ReferenceDef

Defined in Database.Persist.Types.Base

Methods

showsPrec :: Int -> ReferenceDef -> ShowS

show :: ReferenceDef -> String

showList :: [ReferenceDef] -> ShowS

data EmbedEntityDef

An EmbedEntityDef is the same as an EntityDef But it is only used for fieldReference so it only has data needed for embedding

Constructors

EmbedEntityDef

Fields

• embeddedHaskell :: !HaskellName
• embeddedFields :: ![EmbedFieldDef]

Instances

Eq EmbedEntityDef

Defined in Database.Persist.Types.Base

Methods

(==) :: EmbedEntityDef -> EmbedEntityDef -> Bool

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

Ord EmbedEntityDef

Defined in Database.Persist.Types.Base

Methods

compare :: EmbedEntityDef -> EmbedEntityDef -> Ordering

(<) :: EmbedEntityDef -> EmbedEntityDef -> Bool

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

(>) :: EmbedEntityDef -> EmbedEntityDef -> Bool

(>=) :: EmbedEntityDef -> EmbedEntityDef -> Bool

max :: EmbedEntityDef -> EmbedEntityDef -> EmbedEntityDef

min :: EmbedEntityDef -> EmbedEntityDef -> EmbedEntityDef

Read EmbedEntityDef

Defined in Database.Persist.Types.Base

Methods

readsPrec :: Int -> ReadS EmbedEntityDef

readList :: ReadS [EmbedEntityDef]

readPrec :: ReadPrec EmbedEntityDef

readListPrec :: ReadPrec [EmbedEntityDef]

Show EmbedEntityDef

Defined in Database.Persist.Types.Base

Methods

showsPrec :: Int -> EmbedEntityDef -> ShowS

show :: EmbedEntityDef -> String

showList :: [EmbedEntityDef] -> ShowS

data EmbedFieldDef

An EmbedFieldDef is the same as a FieldDef But it is only used for embeddedFields so it only has data needed for embedding

Constructors

EmbedFieldDef

Fields

• emFieldDB :: !DBName
• emFieldEmbed :: Maybe EmbedEntityDef
• emFieldCycle :: Maybe HaskellName

  emFieldEmbed can create a cycle (issue #311) when a cycle is detected, emFieldEmbed will be Nothing and emFieldCycle will be Just

Instances

Eq EmbedFieldDef

Defined in Database.Persist.Types.Base

Methods

(==) :: EmbedFieldDef -> EmbedFieldDef -> Bool

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

Ord EmbedFieldDef

Defined in Database.Persist.Types.Base

Methods

compare :: EmbedFieldDef -> EmbedFieldDef -> Ordering

(<) :: EmbedFieldDef -> EmbedFieldDef -> Bool

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

(>) :: EmbedFieldDef -> EmbedFieldDef -> Bool

(>=) :: EmbedFieldDef -> EmbedFieldDef -> Bool

max :: EmbedFieldDef -> EmbedFieldDef -> EmbedFieldDef

min :: EmbedFieldDef -> EmbedFieldDef -> EmbedFieldDef

Read EmbedFieldDef

Defined in Database.Persist.Types.Base

Methods

readsPrec :: Int -> ReadS EmbedFieldDef

readList :: ReadS [EmbedFieldDef]

readPrec :: ReadPrec EmbedFieldDef

readListPrec :: ReadPrec [EmbedFieldDef]

Show EmbedFieldDef

Defined in Database.Persist.Types.Base

Methods

showsPrec :: Int -> EmbedFieldDef -> ShowS

show :: EmbedFieldDef -> String

showList :: [EmbedFieldDef] -> ShowS

toEmbedEntityDef :: EntityDef -> EmbedEntityDef

data UniqueDef

Constructors

UniqueDef

Fields

• uniqueHaskell :: !HaskellName
• uniqueDBName :: !DBName
• uniqueFields :: ![(HaskellName, DBName)]
• uniqueAttrs :: ![Attr]

Instances

Eq UniqueDef

Defined in Database.Persist.Types.Base

Methods

(==) :: UniqueDef -> UniqueDef -> Bool

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

Ord UniqueDef

Defined in Database.Persist.Types.Base

Methods

compare :: UniqueDef -> UniqueDef -> Ordering

(<) :: UniqueDef -> UniqueDef -> Bool

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

(>) :: UniqueDef -> UniqueDef -> Bool

(>=) :: UniqueDef -> UniqueDef -> Bool

max :: UniqueDef -> UniqueDef -> UniqueDef

min :: UniqueDef -> UniqueDef -> UniqueDef

Read UniqueDef

Defined in Database.Persist.Types.Base

Methods

readsPrec :: Int -> ReadS UniqueDef

readList :: ReadS [UniqueDef]

readPrec :: ReadPrec UniqueDef

readListPrec :: ReadPrec [UniqueDef]

Show UniqueDef

Defined in Database.Persist.Types.Base

Methods

showsPrec :: Int -> UniqueDef -> ShowS

show :: UniqueDef -> String

showList :: [UniqueDef] -> ShowS

data CompositeDef

Constructors

CompositeDef

Fields

• compositeFields :: ![FieldDef]
• compositeAttrs :: ![Attr]

Instances

Eq CompositeDef

Defined in Database.Persist.Types.Base

Methods

(==) :: CompositeDef -> CompositeDef -> Bool

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

Ord CompositeDef

Defined in Database.Persist.Types.Base

Methods

compare :: CompositeDef -> CompositeDef -> Ordering

(<) :: CompositeDef -> CompositeDef -> Bool

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

(>) :: CompositeDef -> CompositeDef -> Bool

(>=) :: CompositeDef -> CompositeDef -> Bool

max :: CompositeDef -> CompositeDef -> CompositeDef

min :: CompositeDef -> CompositeDef -> CompositeDef

Read CompositeDef

Defined in Database.Persist.Types.Base

Methods

readsPrec :: Int -> ReadS CompositeDef

readList :: ReadS [CompositeDef]

readPrec :: ReadPrec CompositeDef

readListPrec :: ReadPrec [CompositeDef]

Show CompositeDef

Defined in Database.Persist.Types.Base

Methods

showsPrec :: Int -> CompositeDef -> ShowS

show :: CompositeDef -> String

showList :: [CompositeDef] -> ShowS

type ForeignFieldDef = (HaskellName, DBName)

Used instead of FieldDef to generate a smaller amount of code

data ForeignDef

Constructors

ForeignDef

Fields

• foreignRefTableHaskell :: !HaskellName
• foreignRefTableDBName :: !DBName
• foreignConstraintNameHaskell :: !HaskellName
• foreignConstraintNameDBName :: !DBName
• foreignFieldCascade :: !FieldCascade

  Determine how the field will cascade on updates and deletions.

  Since: 2.11.0

• foreignFields :: ![(ForeignFieldDef, ForeignFieldDef)]
• foreignAttrs :: ![Attr]
• foreignNullable :: Bool
• foreignToPrimary :: Bool

  Determines if the reference is towards a Primary Key or not.

  Since: 2.11.0

Instances

Eq ForeignDef

Defined in Database.Persist.Types.Base

Methods

(==) :: ForeignDef -> ForeignDef -> Bool

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

Ord ForeignDef

Defined in Database.Persist.Types.Base

Methods

compare :: ForeignDef -> ForeignDef -> Ordering

(<) :: ForeignDef -> ForeignDef -> Bool

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

(>) :: ForeignDef -> ForeignDef -> Bool

(>=) :: ForeignDef -> ForeignDef -> Bool

max :: ForeignDef -> ForeignDef -> ForeignDef

min :: ForeignDef -> ForeignDef -> ForeignDef

Read ForeignDef

Defined in Database.Persist.Types.Base

Methods

readsPrec :: Int -> ReadS ForeignDef

readList :: ReadS [ForeignDef]

readPrec :: ReadPrec ForeignDef

readListPrec :: ReadPrec [ForeignDef]

Show ForeignDef

Defined in Database.Persist.Types.Base

Methods

showsPrec :: Int -> ForeignDef -> ShowS

show :: ForeignDef -> String

showList :: [ForeignDef] -> ShowS

data FieldCascade

This datatype describes how a foreign reference field cascades deletes or updates.

This type is used in both parsing the model definitions and performing migrations. A Nothing in either of the field values means that the user has not specified a CascadeAction. An unspecified CascadeAction is defaulted to Restrict when doing migrations.

Since: 2.11.0

Constructors

FieldCascade

Fields

• fcOnUpdate :: !(Maybe CascadeAction)
• fcOnDelete :: !(Maybe CascadeAction)

Instances

Eq FieldCascade

Defined in Database.Persist.Types.Base

Methods

(==) :: FieldCascade -> FieldCascade -> Bool

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

Ord FieldCascade

Defined in Database.Persist.Types.Base

Methods

compare :: FieldCascade -> FieldCascade -> Ordering

(<) :: FieldCascade -> FieldCascade -> Bool

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

(>) :: FieldCascade -> FieldCascade -> Bool

(>=) :: FieldCascade -> FieldCascade -> Bool

max :: FieldCascade -> FieldCascade -> FieldCascade

min :: FieldCascade -> FieldCascade -> FieldCascade

Read FieldCascade

Defined in Database.Persist.Types.Base

Methods

readsPrec :: Int -> ReadS FieldCascade

readList :: ReadS [FieldCascade]

readPrec :: ReadPrec FieldCascade

readListPrec :: ReadPrec [FieldCascade]

Show FieldCascade

Defined in Database.Persist.Types.Base

Methods

showsPrec :: Int -> FieldCascade -> ShowS

show :: FieldCascade -> String

showList :: [FieldCascade] -> ShowS

noCascade :: FieldCascade

A FieldCascade that does nothing.

Since: 2.11.0

renderFieldCascade :: FieldCascade -> Text

Renders a FieldCascade value such that it can be used in SQL migrations.

Since: 2.11.0

data CascadeAction

An action that might happen on a deletion or update on a foreign key change.

Since: 2.11.0

Constructors

Cascade

Restrict

SetNull

SetDefault

Instances

Eq CascadeAction

Defined in Database.Persist.Types.Base

Methods

(==) :: CascadeAction -> CascadeAction -> Bool

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

Ord CascadeAction

Defined in Database.Persist.Types.Base

Methods

compare :: CascadeAction -> CascadeAction -> Ordering

(<) :: CascadeAction -> CascadeAction -> Bool

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

(>) :: CascadeAction -> CascadeAction -> Bool

(>=) :: CascadeAction -> CascadeAction -> Bool

max :: CascadeAction -> CascadeAction -> CascadeAction

min :: CascadeAction -> CascadeAction -> CascadeAction

Read CascadeAction

Defined in Database.Persist.Types.Base

Methods

readsPrec :: Int -> ReadS CascadeAction

readList :: ReadS [CascadeAction]

readPrec :: ReadPrec CascadeAction

readListPrec :: ReadPrec [CascadeAction]

Show CascadeAction

Defined in Database.Persist.Types.Base

Methods

showsPrec :: Int -> CascadeAction -> ShowS

show :: CascadeAction -> String

showList :: [CascadeAction] -> ShowS

renderCascadeAction :: CascadeAction -> Text

Render a CascadeAction to Text such that it can be used in a SQL command.

Since: 2.11.0

data PersistException

Constructors

PersistError Text

Generic Exception

PersistMarshalError Text

PersistInvalidField Text

PersistForeignConstraintUnmet Text

PersistMongoDBError Text

PersistMongoDBUnsupported Text

Instances

Show PersistException

Defined in Database.Persist.Types.Base

Methods

showsPrec :: Int -> PersistException -> ShowS

show :: PersistException -> String

showList :: [PersistException] -> ShowS

Exception PersistException

Defined in Database.Persist.Types.Base

Methods

toException :: PersistException -> SomeException

fromException :: SomeException -> Maybe PersistException

displayException :: PersistException -> String

Error PersistException

Defined in Database.Persist.Types.Base

Methods

noMsg :: PersistException

strMsg :: String -> PersistException

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 ByteString

Using PersistLiteral allows you to use types or keywords specific to a particular backend.

PersistLiteralEscaped ByteString

Similar to PersistLiteral, but escapes the ByteString.

PersistDbSpecific ByteString

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 or PersistLiteralEscaped based on your needs.

Using PersistDbSpecific allows you to use types specific to a particular backend. For example, below is a simple example of the PostGIS geography type:

data Geo = Geo ByteString

instance PersistField Geo where
  toPersistValue (Geo t) = PersistDbSpecific t

  fromPersistValue (PersistDbSpecific t) = Right $ Geo $ Data.ByteString.concat ["'", t, "'"]
  fromPersistValue _ = Left "Geo values must be converted from PersistDbSpecific"

instance PersistFieldSql Geo where
  sqlType _ = SqlOther "GEOGRAPHY(POINT,4326)"

toPoint :: Double -> Double -> Geo
toPoint lat lon = Geo $ Data.ByteString.concat ["'POINT(", ps $ lon, " ", ps $ lat, ")'"]
  where ps = Data.Text.pack . show

If Foo has a geography field, we can then perform insertions like the following:

insert $ Foo (toPoint 44 44)

Instances

Eq PersistValue

Defined in Database.Persist.Types.Base

Methods

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

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

Ord PersistValue

Defined in Database.Persist.Types.Base

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

Read PersistValue

Defined in Database.Persist.Types.Base

Methods

readsPrec :: Int -> ReadS PersistValue

readList :: ReadS [PersistValue]

readPrec :: ReadPrec PersistValue

readListPrec :: ReadPrec [PersistValue]

Show PersistValue

Defined in Database.Persist.Types.Base

Methods

showsPrec :: Int -> PersistValue -> ShowS

show :: PersistValue -> String

showList :: [PersistValue] -> ShowS

ToJSON PersistValue

Defined in Database.Persist.Types.Base

Methods

toJSON :: PersistValue -> Value

toEncoding :: PersistValue -> Encoding

toJSONList :: [PersistValue] -> Value

toEncodingList :: [PersistValue] -> Encoding

FromJSON PersistValue

Defined in Database.Persist.Types.Base

Methods

parseJSON :: Value -> Parser PersistValue

parseJSONList :: Value -> Parser [PersistValue]

ToHttpApiData PersistValue

Defined in Database.Persist.Types.Base

Methods

toUrlPiece :: PersistValue -> Text

toEncodedUrlPiece :: PersistValue -> Builder

toHeader :: PersistValue -> ByteString

toQueryParam :: PersistValue -> Text

FromHttpApiData PersistValue

Defined in Database.Persist.Types.Base

Methods

parseUrlPiece :: Text -> Either Text PersistValue

parseHeader :: ByteString -> Either Text PersistValue

parseQueryParam :: Text -> Either Text PersistValue

PathPiece PersistValue

Defined in Database.Persist.Types.Base

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 SqlType

A SQL data type. Naming attempts to reflect the underlying Haskell datatypes, eg SqlString instead of SqlVarchar. Different SQL databases may have different translations for these types.

Constructors

SqlString

SqlInt32

SqlInt64

SqlReal

SqlNumeric Word32 Word32

SqlBool

SqlDay

SqlTime

SqlDayTime

Always uses UTC timezone

SqlBlob

SqlOther Text

a backend-specific name

Instances

Eq SqlType

Defined in Database.Persist.Types.Base

Methods

(==) :: SqlType -> SqlType -> Bool

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

Ord SqlType

Defined in Database.Persist.Types.Base

Methods

compare :: SqlType -> SqlType -> Ordering

(<) :: SqlType -> SqlType -> Bool

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

(>) :: SqlType -> SqlType -> Bool

(>=) :: SqlType -> SqlType -> Bool

max :: SqlType -> SqlType -> SqlType

min :: SqlType -> SqlType -> SqlType

Read SqlType

Defined in Database.Persist.Types.Base

Methods

readsPrec :: Int -> ReadS SqlType

readList :: ReadS [SqlType]

readPrec :: ReadPrec SqlType

readListPrec :: ReadPrec [SqlType]

Show SqlType

Defined in Database.Persist.Types.Base

Methods

showsPrec :: Int -> SqlType -> ShowS

show :: SqlType -> String

showList :: [SqlType] -> ShowS

data PersistFilter

Constructors

Eq

Ne

Gt

Lt

Ge

Le

In

NotIn

BackendSpecificFilter Text

Instances

Read PersistFilter

Defined in Database.Persist.Types.Base

Methods

readsPrec :: Int -> ReadS PersistFilter

readList :: ReadS [PersistFilter]

readPrec :: ReadPrec PersistFilter

readListPrec :: ReadPrec [PersistFilter]

Show PersistFilter

Defined in Database.Persist.Types.Base

Methods

showsPrec :: Int -> PersistFilter -> ShowS

show :: PersistFilter -> String

showList :: [PersistFilter] -> ShowS

data UpdateException

Constructors

KeyNotFound String

UpsertError String

Instances

Show UpdateException

Defined in Database.Persist.Types.Base

Methods

showsPrec :: Int -> UpdateException -> ShowS

show :: UpdateException -> String

showList :: [UpdateException] -> ShowS

Exception UpdateException

Defined in Database.Persist.Types.Base

Methods

toException :: UpdateException -> SomeException

fromException :: SomeException -> Maybe UpdateException

displayException :: UpdateException -> String

data OnlyUniqueException

Constructors

OnlyUniqueException String

Instances

Show OnlyUniqueException

Defined in Database.Persist.Types.Base

Methods

showsPrec :: Int -> OnlyUniqueException -> ShowS

show :: OnlyUniqueException -> String

showList :: [OnlyUniqueException] -> ShowS

Exception OnlyUniqueException

Defined in Database.Persist.Types.Base

Methods

toException :: OnlyUniqueException -> SomeException

fromException :: SomeException -> Maybe OnlyUniqueException

displayException :: OnlyUniqueException -> String

data PersistUpdate

Constructors

Assign

Add

Subtract

Multiply

Divide

BackendSpecificUpdate Text

Instances

Read PersistUpdate

Defined in Database.Persist.Types.Base

Methods

readsPrec :: Int -> ReadS PersistUpdate

readList :: ReadS [PersistUpdate]

readPrec :: ReadPrec PersistUpdate

readListPrec :: ReadPrec [PersistUpdate]

Show PersistUpdate

Defined in Database.Persist.Types.Base

Methods

showsPrec :: Int -> PersistUpdate -> ShowS

show :: PersistUpdate -> String

showList :: [PersistUpdate] -> ShowS

data SomePersistField

Constructors

forall a.PersistField a => SomePersistField a

Instances

PersistField SomePersistField

Defined in Database.Persist.Class.PersistField

Methods

toPersistValue :: SomePersistField -> PersistValue

fromPersistValue :: PersistValue -> Either Text SomePersistField

data Update record

Updating a database entity.

Persistent users use combinators to create these.

Constructors

forall typ.PersistField typ => Update

Fields

• updateField :: EntityField record typ
• updateValue :: typ
• updateUpdate :: PersistUpdate

BackendUpdate (BackendSpecificUpdate (PersistEntityBackend record) record)

type family BackendSpecificUpdate backend record

data SelectOpt record

Query options.

Persistent users use these directly.

Constructors

forall typ. Asc (EntityField record typ)

forall typ. Desc (EntityField record typ)

OffsetBy Int

LimitTo Int

data Filter record

Filters which are available for select, updateWhere and deleteWhere. Each filter constructor specifies the field being filtered on, the type of comparison applied (equals, not equals, etc) and the argument for the comparison.

Persistent users use combinators to create these.

Note that it's important to be careful about the PersistFilter that you are using, if you use this directly. For example, using the In PersistFilter requires that you have an array- or list-shaped EntityField. It is possible to construct values using this that will create malformed runtime values.

Constructors

forall typ.PersistField typ => Filter

Fields

• filterField :: EntityField record typ
• filterValue :: FilterValue typ
• filterFilter :: PersistFilter

FilterAnd [Filter record]

convenient for internal use, not needed for the API

FilterOr [Filter record]

BackendFilter (BackendSpecificFilter (PersistEntityBackend record) record)

data FilterValue typ where

Value to filter with. Highly dependant on the type of filter used.

Since: 2.10.0

Constructors

FilterValue :: typ -> FilterValue typ

FilterValues :: [typ] -> FilterValue typ

UnsafeValue :: forall a typ. PersistField a => a -> FilterValue typ

type family BackendSpecificFilter backend record

data family Key record

By default, a backend will automatically generate the key Instead you can specify a Primary key made up of unique values.

Instances

(PersistEntity a, PersistEntityBackend a ~ backend, IsPersistBackend backend) => RawSql (Key a)

Defined in Database.Persist.Sql.Class

Methods

rawSqlCols :: (DBName -> Text) -> Key a -> (Int, [Text])

rawSqlColCountReason :: Key a -> String

rawSqlProcessRow :: [PersistValue] -> Either Text (Key a)

data Entity record

Datatype that represents an entity, with both its Key and its Haskell record representation.

When using a SQL-based backend (such as SQLite or PostgreSQL), an Entity may take any number of columns depending on how many fields it has. In order to reconstruct your entity on the Haskell side, persistent needs all of your entity columns and in the right order. Note that you don't need to worry about this when using persistent's API since everything is handled correctly behind the scenes.

However, if you want to issue a raw SQL command that returns an Entity, then you have to be careful with the column order. While you could use SELECT Entity.* WHERE ... and that would work most of the time, there are times when the order of the columns on your database is different from the order that persistent expects (for example, if you add a new field in the middle of you entity definition and then use the migration code -- persistent will expect the column to be in the middle, but your DBMS will put it as the last column). So, instead of using a query like the one above, you may use rawSql (from the Database.Persist.GenericSql module) with its /entity selection placeholder/ (a double question mark ??). Using rawSql the query above must be written as SELECT ?? WHERE ... Then rawSql will replace ?? with the list of all columns that we need from your entity in the right order. If your query returns two entities (i.e. (Entity backend a, Entity backend b)), then you must you use SELECT ??, ?? WHERE ..., and so on.

Constructors

Entity

Fields

• entityKey :: Key record
• entityVal :: record

Instances

(Eq (Key record), Eq record) => Eq (Entity record)

Defined in Database.Persist.Class.PersistEntity

Methods

(==) :: Entity record -> Entity record -> Bool

(/=) :: Entity record -> Entity record -> Bool

(Ord (Key record), Ord record) => Ord (Entity record)

Defined in Database.Persist.Class.PersistEntity

Methods

compare :: Entity record -> Entity record -> Ordering

(<) :: Entity record -> Entity record -> Bool

(<=) :: Entity record -> Entity record -> Bool

(>) :: Entity record -> Entity record -> Bool

(>=) :: Entity record -> Entity record -> Bool

max :: Entity record -> Entity record -> Entity record

min :: Entity record -> Entity record -> Entity record

(Read (Key record), Read record) => Read (Entity record)

Defined in Database.Persist.Class.PersistEntity

Methods

readsPrec :: Int -> ReadS (Entity record)

readList :: ReadS [Entity record]

readPrec :: ReadPrec (Entity record)

readListPrec :: ReadPrec [Entity record]

(Show (Key record), Show record) => Show (Entity record)

Defined in Database.Persist.Class.PersistEntity

Methods

showsPrec :: Int -> Entity record -> ShowS

show :: Entity record -> String

showList :: [Entity record] -> ShowS

(Generic (Key record), Generic record) => Generic (Entity record)

Defined in Database.Persist.Class.PersistEntity

Associated Types

type Rep (Entity record) :: Type -> Type

Methods

from :: Entity record -> Rep (Entity record) x

to :: Rep (Entity record) x -> Entity record

(PersistEntity record, PersistField record, PersistField (Key record)) => PersistField (Entity record)

Defined in Database.Persist.Class.PersistEntity

Methods

toPersistValue :: Entity record -> PersistValue

fromPersistValue :: PersistValue -> Either Text (Entity record)

(PersistField record, PersistEntity record) => PersistFieldSql (Entity record)

Defined in Database.Persist.Sql.Class

Methods

sqlType :: Proxy (Entity record) -> SqlType

(PersistEntity record, PersistEntityBackend record ~ backend, IsPersistBackend backend) => RawSql (Entity record)

Defined in Database.Persist.Sql.Class

Methods

rawSqlCols :: (DBName -> Text) -> Entity record -> (Int, [Text])

rawSqlColCountReason :: Entity record -> String

rawSqlProcessRow :: [PersistValue] -> Either Text (Entity record)

type Rep (Entity record)

Defined in Database.Persist.Class.PersistEntity

type Rep (Entity record) = D1 ('MetaData "Entity" "Database.Persist.Class.PersistEntity" "persistent-2.11.0.0-7MZ4QawVRfZ1UMDL6jceVl" 'False) (C1 ('MetaCons "Entity" 'PrefixI 'True) (S1 ('MetaSel ('Just "entityKey") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 (Key record)) :*: S1 ('MetaSel ('Just "entityVal") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 record)))

newtype OverflowNatural

Prior to persistent-2.11.0, we provided an instance of PersistField for the Natural type. This was in error, because Natural represents an infinite value, and databases don't have reasonable types for this.

The instance for Natural used the Int64 underlying type, which will cause underflow and overflow errors. This type has the exact same code in the instances, and will work seamlessly.

A more appropriate type for this is the Word series of types from Data.Word. These have a bounded size, are guaranteed to be non-negative, and are quite efficient for the database to store.

Since: 2.11.0

Constructors

OverflowNatural

Fields

• unOverflowNatural :: Natural

Instances

Eq OverflowNatural

Defined in Database.Persist.Class.PersistField

Methods

(==) :: OverflowNatural -> OverflowNatural -> Bool

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

Ord OverflowNatural

Defined in Database.Persist.Class.PersistField

Methods

compare :: OverflowNatural -> OverflowNatural -> Ordering

(<) :: OverflowNatural -> OverflowNatural -> Bool

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

(>) :: OverflowNatural -> OverflowNatural -> Bool

(>=) :: OverflowNatural -> OverflowNatural -> Bool

max :: OverflowNatural -> OverflowNatural -> OverflowNatural

min :: OverflowNatural -> OverflowNatural -> OverflowNatural

Show OverflowNatural

Defined in Database.Persist.Class.PersistField

Methods

showsPrec :: Int -> OverflowNatural -> ShowS

show :: OverflowNatural -> String

showList :: [OverflowNatural] -> ShowS

PersistField OverflowNatural

Defined in Database.Persist.Class.PersistField

Methods

toPersistValue :: OverflowNatural -> PersistValue

fromPersistValue :: PersistValue -> Either Text OverflowNatural

PersistFieldSql OverflowNatural

This type uses the SqlInt64 version, which will exhibit overflow and underflow behavior. Additionally, it permits negative values in the database, which isn't ideal.

Since: 2.11.0

Defined in Database.Persist.Sql.Class

Methods

sqlType :: Proxy OverflowNatural -> SqlType