composite-opaleye-0.3.1.0: Opaleye SQL for Frames records

Safe HaskellNone
LanguageHaskell2010

Composite.Opaleye.RecordTable

Synopsis

Documentation

class DefaultRecTableField write read where Source #

Helper typeclass which picks which of required or optional to use for a pair of write column type and read column type.

DefaultRecTableField (Maybe (Column a)) (Column a) uses optional. DefaultRecTableField (Column a) (Column a) uses required.

Minimal complete definition

defaultRecTableField

class DefaultRecTable write read where Source #

Type class for producing a default TableProperties schema for some expected record types. required and optional are chosen automatically and the column is named after the record fields, using NamedField to reflect the field names.

For example, given:

 type WriteRec = Record '["id" :-> Maybe (Column PGInt8), "name" :-> Column PGText]
 type ReadRec  = Record '["id" :->        Column PGInt8 , "name" :-> Column PGText]

This:

 defaultRecTable :: TableProperties WriteRec ReadRec

Is equivalent to:

pReq (optional "id" &: required "name" &: Nil)

Alternately, use pReq and the usual Opaleye required and optional.

Minimal complete definition

defaultRecTable

Instances

DefaultRecTable ([] *) ([] *) Source # 
(KnownSymbol s, DefaultRecTableField w r, DefaultRecTable writes reads) => DefaultRecTable ((:) * ((:->) s w) writes) ((:) * ((:->) s r) reads) Source # 

Methods

defaultRecTable :: TableProperties (Rec * Identity ((* ': (s :-> w)) writes)) (Rec * Identity ((* ': (s :-> r)) reads)) Source #