Modulepersistent-2.18.1.0Haskell2010

Database.Persist.FieldDef

Contents

The FieldDef type
Setters
Helpers
FieldCascade

Synopsis

data FieldDef
value setFieldAttrs
value overFieldAttrs
value addFieldAttr
value isFieldNullable
value isFieldMaybe
value isFieldNotGenerated
value isHaskellField
data FieldCascade
value renderFieldCascade
value renderCascadeAction
value noCascade
data CascadeAction

Packagepersistent-2.18.1.0
Exports13
LanguageHaskell2010
LicenceMIT
SourceFieldDef.hs

The FieldDef type

datadata FieldDef

Source#

A FieldDef represents the inormation 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.

Instances5Eq, Ord, Read, Show, Lift

Eq FieldDefDefined in persistent-2.18.1.0 · Database.Persist.Types.Base
Ord FieldDefDefined in persistent-2.18.1.0 · Database.Persist.Types.Base
Read FieldDefDefined in persistent-2.18.1.0 · Database.Persist.Types.Base
Show FieldDefDefined in persistent-2.18.1.0 · Database.Persist.Types.Base
Lift FieldDefDefined in persistent-2.18.1.0 · Database.Persist.Types.Base

Setters

valuesetFieldAttrs :: [FieldAttr] -> FieldDef -> FieldDef

Source#

Replace the FieldDef FieldAttr with the new list.

valueoverFieldAttrs :: ([FieldAttr] -> [FieldAttr]) -> FieldDef -> FieldDef

Source#

Modify the list of field attributes.

valueaddFieldAttr :: FieldAttr -> FieldDef -> FieldDef

Source#

Add an attribute to the list of field attributes.

Helpers

valueisFieldNullable :: FieldDef -> IsNullable

Source#

Check if the field definition is nullable

valueisFieldMaybe :: FieldDef -> Bool

Source#

Check if the field is `Maybe a`

valueisFieldNotGenerated :: FieldDef -> Bool

valueisHaskellField :: FieldDef -> Bool

Source#

Returns True if the FieldDef does not have a MigrationOnly or SafeToRemove flag from the QuasiQuoter.

FieldCascade

datadata FieldCascade

Source#

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.

Constructors

FieldCascade
- fcOnUpdate :: !Maybe CascadeAction
- fcOnDelete :: !Maybe CascadeAction

Instances5Eq, Ord, Read, Show, Lift

Eq FieldCascadeDefined in persistent-2.18.1.0 · Database.Persist.Types.Base
Ord FieldCascadeDefined in persistent-2.18.1.0 · Database.Persist.Types.Base
Read FieldCascadeDefined in persistent-2.18.1.0 · Database.Persist.Types.Base
Show FieldCascadeDefined in persistent-2.18.1.0 · Database.Persist.Types.Base
Lift FieldCascadeDefined in persistent-2.18.1.0 · Database.Persist.Types.Base

valuerenderFieldCascade :: FieldCascade -> Text

Source#

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

valuerenderCascadeAction :: CascadeAction -> Text

Source#

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

valuenoCascade :: FieldCascade

Source#

A FieldCascade that does nothing.

datadata CascadeAction

Source#

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

Cascade Restrict SetNull SetDefault NoAction

Instances5Eq, Ord, Read, Show, Lift

Eq CascadeActionDefined in persistent-2.18.1.0 · Database.Persist.Types.Base
Ord CascadeActionDefined in persistent-2.18.1.0 · Database.Persist.Types.Base
Read CascadeActionDefined in persistent-2.18.1.0 · Database.Persist.Types.Base
Show CascadeActionDefined in persistent-2.18.1.0 · Database.Persist.Types.Base
Lift CascadeActionDefined in persistent-2.18.1.0 · Database.Persist.Types.Base