esqueleto-3.5.11.2: Type-safe EDSL for SQL queries on persistent backends.

Safe Haskell | Safe-Inferred
Language | Haskell2010

Database.Esqueleto.Experimental.ToMaybe

# Documentation

type family Nullable a where ... Source #

Equations

Nullable (Maybe a) = a |
Nullable a = a |

class ToMaybe a where Source #

Associated Types

type ToMaybeT a Source #

Methods

toMaybe :: a -> ToMaybeT a Source #

#### Instances

Instances details

ToMaybe (SqlExpr (Value a)) Source # |
Instance details Defined in Database.Esqueleto.Experimental.ToMaybe Associated Types type ToMaybeT (SqlExpr (Value a)) Source # Methods toMaybe :: SqlExpr (Value a) -> ToMaybeT (SqlExpr (Value a)) Source #
ToMaybe (SqlExpr (Entity a)) Source # |
Instance details Defined in Database.Esqueleto.Experimental.ToMaybe Associated Types type ToMaybeT (SqlExpr (Entity a)) Source # Methods toMaybe :: SqlExpr (Entity a) -> ToMaybeT (SqlExpr (Entity a)) Source #
ToMaybe (SqlExpr (Maybe a)) Source # |
Instance details Defined in Database.Esqueleto.Experimental.ToMaybe Associated Types type ToMaybeT (SqlExpr (Maybe a)) Source # Methods toMaybe :: SqlExpr (Maybe a) -> ToMaybeT (SqlExpr (Maybe a)) Source #
(ToMaybe a, ToMaybe b) => ToMaybe (a :& b) Source # |
Instance details Defined in Database.Esqueleto.Experimental.From.Join Associated Types type ToMaybeT (a :& b) Source # Methods toMaybe :: (a :& b) -> ToMaybeT (a :& b) Source #
(ToMaybe a, ToMaybe b) => ToMaybe (a, b) Source # |
Instance details Defined in Database.Esqueleto.Experimental.ToMaybe Associated Types type ToMaybeT (a, b) Source # Methods toMaybe :: (a, b) -> ToMaybeT (a, b) Source #
(ToMaybe a, ToMaybe b, ToMaybe c) => ToMaybe (a, b, c) Source # |
Instance details Defined in Database.Esqueleto.Experimental.ToMaybe Associated Types type ToMaybeT (a, b, c) Source # Methods toMaybe :: (a, b, c) -> ToMaybeT (a, b, c) Source #
(ToMaybe a, ToMaybe b, ToMaybe c, ToMaybe d) => ToMaybe (a, b, c, d) Source # |
Instance details Defined in Database.Esqueleto.Experimental.ToMaybe Associated Types type ToMaybeT (a, b, c, d) Source # Methods toMaybe :: (a, b, c, d) -> ToMaybeT (a, b, c, d) Source #
(ToMaybe a, ToMaybe b, ToMaybe c, ToMaybe d, ToMaybe e) => ToMaybe (a, b, c, d, e) Source # |
Instance details Defined in Database.Esqueleto.Experimental.ToMaybe Associated Types type ToMaybeT (a, b, c, d, e) Source # Methods toMaybe :: (a, b, c, d, e) -> ToMaybeT (a, b, c, d, e) Source #
(ToMaybe a, ToMaybe b, ToMaybe c, ToMaybe d, ToMaybe e, ToMaybe f) => ToMaybe (a, b, c, d, e, f) Source # |
Instance details Defined in Database.Esqueleto.Experimental.ToMaybe Associated Types type ToMaybeT (a, b, c, d, e, f) Source # Methods toMaybe :: (a, b, c, d, e, f) -> ToMaybeT (a, b, c, d, e, f) Source #
(ToMaybe a, ToMaybe b, ToMaybe c, ToMaybe d, ToMaybe e, ToMaybe f, ToMaybe g) => ToMaybe (a, b, c, d, e, f, g) Source # |
Instance details Defined in Database.Esqueleto.Experimental.ToMaybe Associated Types type ToMaybeT (a, b, c, d, e, f, g) Source # Methods toMaybe :: (a, b, c, d, e, f, g) -> ToMaybeT (a, b, c, d, e, f, g) Source #
(ToMaybe a, ToMaybe b, ToMaybe c, ToMaybe d, ToMaybe e, ToMaybe f, ToMaybe g, ToMaybe h) => ToMaybe (a, b, c, d, e, f, g, h) Source # |
Instance details Defined in Database.Esqueleto.Experimental.ToMaybe Associated Types type ToMaybeT (a, b, c, d, e, f, g, h) Source # Methods toMaybe :: (a, b, c, d, e, f, g, h) -> ToMaybeT (a, b, c, d, e, f, g, h) Source #