Database.Relational.ProjectableClass

This module provides interfaces to preserve constraints of direct product projections.

Literal SQL terms

class ShowConstantTermsSQL a where

ShowConstantTermsSQL a is implicit rule to derive function to convert from haskell record type a into constant SQL terms.

Generic programming (https://downloads.haskell.org/~ghc/latest/docs/html/users_guide/glasgow_exts.html#generic-programming) with default signature is available for ShowConstantTermsSQL class, so you can make instance like below:

  {-# LANGUAGE DeriveGeneric #-}
  import GHC.Generics (Generic)
  --
  data Foo = Foo { ... } deriving Generic
  instance ShowConstantTermsSQL Foo

Methods

showConstantTermsSQL' :: a -> DList StringSQL

showConstantTermsSQL' :: (Generic a, GShowConstantTermsSQL (Rep a)) => a -> DList StringSQL

showConstantTermsSQL :: ShowConstantTermsSQL a => a -> [StringSQL]

Convert from haskell record to SQL terms list.

type StringSQL = Keyword

String wrap type for SQL strings.