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

Documentation

module Opaleye.Adaptors

module Opaleye.Aggregate

module Opaleye.Binary

type family Column a where ...

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

Equations

Column (Nullable a) = FieldNullable a

Column a = Field a

data Nullable a

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

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

Treat a Field_ 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.

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

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.

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

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

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