Database.Relational.ProjectableExtended

This module defines operators on various projected records.

Projection for nested Maybes

class ProjectableFlattenMaybe a b where

Interface to compose phantom Maybe nested type.

Minimal complete definition

flatten

Methods

flatten :: ProjectableMaybe p => p a -> p b

Instances

ProjectableFlattenMaybe (Maybe a) b => ProjectableFlattenMaybe (Maybe (Maybe a)) b

Compose Maybe type in record phantom type.

Methods

flatten :: ProjectableMaybe p => p (Maybe (Maybe a)) -> p b

ProjectableFlattenMaybe (Maybe a) (Maybe a)

Not Maybe type is not processed.

Methods

flatten :: ProjectableMaybe p => p (Maybe a) -> p (Maybe a)

flattenPiMaybe

Arguments

:: (PersistableWidth a, ProjectableMaybe (Record cont), ProjectableFlattenMaybe (Maybe b) c)

=> Record cont (Maybe a)

Source Record. Maybe phantom type

-> Pi a b

Projection path

-> Record cont c

Narrower Record. Flatten Maybe phantom type

Get narrower record with flatten leaf phantom Maybe types along with projection path.

Get narrower records

(!) infixl 8

Arguments

:: PersistableWidth a

=> Record c a

Source Record

-> Pi a b

Record path

-> Record c b

Narrower projected object

Get narrower record along with projection path.

(?!) infixl 8

Arguments

:: PersistableWidth a

=> Record c (Maybe a)

Source Record. Maybe type

-> Pi a b

Record path

-> Record c (Maybe b)

Narrower projected object. Maybe type result

Get narrower record along with projection path Maybe phantom functor is map-ed.

(?!?) infixl 8

Arguments

:: PersistableWidth a

=> Record c (Maybe a)

Source Record. Maybe phantom type

-> Pi a (Maybe b)

Record path. Maybe type leaf

-> Record c (Maybe b)

Narrower projected object. Maybe phantom type result

Get narrower record along with projection path and project into result record type. Source record Maybe phantom functor and projection path leaf Maybe functor are join-ed.

(!??) infixl 8

Arguments

:: (PersistableWidth a, ProjectableMaybe (Record cont), ProjectableFlattenMaybe (Maybe b) c)

=> Record cont (Maybe a)

Source Record. Maybe phantom type

-> Pi a b

Projection path

-> Record cont c

Narrower flatten and projected object.

Get narrower record with flatten leaf phantom Maybe types along with projection path.

Aggregate functions

unsafeAggregateOp :: (AggregatedContext ac, SqlContext ac) => Keyword -> Record Flat a -> Record ac b

Unsafely make aggregation uni-operator from SQL keyword.

count :: (Integral b, AggregatedContext ac, SqlContext ac) => Record Flat a -> Record ac b

Aggregation function COUNT.

sum' :: (Num a, AggregatedContext ac, SqlContext ac) => Record Flat a -> Record ac (Maybe a)

Aggregation function SUM.

sumMaybe :: (Num a, AggregatedContext ac, SqlContext ac) => Record Flat (Maybe a) -> Record ac (Maybe a)

Aggregation function SUM.

avg :: (Num a, Fractional b, AggregatedContext ac, SqlContext ac) => Record Flat a -> Record ac (Maybe b)

Aggregation function AVG.

avgMaybe :: (Num a, Fractional b, AggregatedContext ac, SqlContext ac) => Record Flat (Maybe a) -> Record ac (Maybe b)

Aggregation function AVG.

max' :: (Ord a, AggregatedContext ac, SqlContext ac) => Record Flat a -> Record ac (Maybe a)

Aggregation function MAX.

maxMaybe :: (Ord a, AggregatedContext ac, SqlContext ac) => Record Flat (Maybe a) -> Record ac (Maybe a)

Aggregation function MAX.

min' :: (Ord a, AggregatedContext ac, SqlContext ac) => Record Flat a -> Record ac (Maybe a)

Aggregation function MIN.

minMaybe :: (Ord a, AggregatedContext ac, SqlContext ac) => Record Flat (Maybe a) -> Record ac (Maybe a)

Aggregation function MIN.

every :: (AggregatedContext ac, SqlContext ac) => Predicate Flat -> Record ac (Maybe Bool)

Aggregation function EVERY.

any' :: (AggregatedContext ac, SqlContext ac) => Predicate Flat -> Record ac (Maybe Bool)

Aggregation function ANY.

some' :: (AggregatedContext ac, SqlContext ac) => Predicate Flat -> Record ac (Maybe Bool)

Aggregation function SOME.