Moduleopaleye-0.10.8.0Haskell2010

Opaleye

An SQL-generating DSL targeting PostgreSQL. Allows Postgres queries to be written within Haskell in a typesafe and composable fashion.

You might like to look at

Basic tutorial
Manipulation tutorial
Advanced tutorial
If you are confused about the Default typeclass, then the Default explanation

Synopsis

value joinNullable
value unsafeCast
value unsafeCoerceColumn
value unsafeCompositeField
family Column
data Nullable

Packageopaleye-0.10.8.0
Exports6
LanguageHaskell2010
LicenceBSD-3-Clause
SourceOpaleye.hs

module Opaleye.Adaptors

module Opaleye.Aggregate

module Opaleye.Binary

valuejoinNullable :: Column (Nullable (Nullable a)) -> Column (Nullable a)

valueunsafeCast :: String -> Field_ n a -> Field_ n b

Source#

Cast a column to any other type. Implements Postgres's :: or CAST( ... AS ... ) operations. This is safe for some conversions, such as uuid to text.

valueunsafeCoerceColumn :: Field_ n a -> Field_ n' b

Source#

Treat a Column as though it were of a different type. If such a treatment is not valid then Postgres may fail with an error at SQL run time.

valueunsafeCompositeField :: Field_ n a -> String -> Field_ n' b

familytype family Column a where

Source#

Do not use. Use Field instead. Will be removed in a later version.

Equations

Column (Nullable a) = FieldNullable a
Column a = Field a

datadata Nullable a

Source#

Only used within a Column, to indicate that it can be NULL. For example, a Column (Nullable SqlText) can be NULL but a Column SqlText cannot.

module Opaleye.Distinct

module Opaleye.Field

module Opaleye.FunctionalJoin

module Opaleye.Join

module Opaleye.Label

module Opaleye.Lateral

module Opaleye.Manipulation

module Opaleye.MaybeFields

module Opaleye.Operators

module Opaleye.Order

module Opaleye.RunSelect

module Opaleye.Sql

module Opaleye.Select

module Opaleye.SqlTypes

module Opaleye.Table

module Opaleye.ToFields

module Opaleye.Values

module Opaleye.With

module Opaleye.Window