Database.Persist.FieldDef · persistent-2.14.6.3

The FieldDef type

1 declaration

datadata FieldDef

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-2.14.6.3 · Database.Persist.Types.Base
Ord FieldDefDefined in persistent-2.14.6.3 · Database.Persist.Types.Base
Read FieldDefDefined in persistent-2.14.6.3 · Database.Persist.Types.Base
Show FieldDefDefined in persistent-2.14.6.3 · Database.Persist.Types.Base
Lift FieldDefDefined in persistent-2.14.6.3 · Database.Persist.Types.Base

Setters

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

#

Replace the FieldDef FieldAttr with the new list.

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

#

Modify the list of field attributes.

valueaddFieldAttr :: FieldAttr -> FieldDef -> FieldDef

#

Add an attribute to the list of field attributes.

Helpers

valueisFieldNullable :: FieldDef -> IsNullable

#

Check if the field definition is nullable

valueisFieldMaybe :: FieldDef -> Bool

#

Check if the field is `Maybe a`

valueisFieldNotGenerated :: FieldDef -> Bool

#

valueisHaskellField :: FieldDef -> Bool

#

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

FieldCascade

5 declarations

datadata 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.

Constructors

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

Instances5Eq, Ord, Read, Show, Lift

Eq FieldCascadeDefined in persistent-2.14.6.3 · Database.Persist.Types.Base
Ord FieldCascadeDefined in persistent-2.14.6.3 · Database.Persist.Types.Base
Read FieldCascadeDefined in persistent-2.14.6.3 · Database.Persist.Types.Base
Show FieldCascadeDefined in persistent-2.14.6.3 · Database.Persist.Types.Base
Lift FieldCascadeDefined in persistent-2.14.6.3 · Database.Persist.Types.Base

valuerenderFieldCascade :: FieldCascade -> Text

#

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

valuerenderCascadeAction :: CascadeAction -> Text

#

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

valuenoCascade :: FieldCascade

#

A FieldCascade that does nothing.

datadata CascadeAction

#

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

Cascade Restrict SetNull SetDefault

Instances5Eq, Ord, Read, Show, Lift

Eq CascadeActionDefined in persistent-2.14.6.3 · Database.Persist.Types.Base
Ord CascadeActionDefined in persistent-2.14.6.3 · Database.Persist.Types.Base
Read CascadeActionDefined in persistent-2.14.6.3 · Database.Persist.Types.Base
Show CascadeActionDefined in persistent-2.14.6.3 · Database.Persist.Types.Base
Lift CascadeActionDefined in persistent-2.14.6.3 · Database.Persist.Types.Base