Database.Relational.Query.Arrow

This module defines arrow version combinators which improves type-safty on building queries. Referencing the local projections may cause to break the result query. It is possible to controls injection of previous local projections by restricting domain type of arrow. This idea is imported from Opaleye:

• https://github.com/tomjaguarpaw/haskell-opaleye
• https://github.com/khibino/haskell-relational-record/issues/19

Importing this module instead of Database.Relational.Query enables to build query using arrow combinators.

Documentation

module Database.Relational.Query

all' :: MonadQuery m => QueryA m () ()

Same as all'. Arrow version.

distinct :: MonadQuery m => QueryA m () ()

Same as distinct. Arrow version.

query :: (MonadQualify ConfigureQuery m, MonadQuery m) => Relation () r -> QueryA m () (Projection Flat r)

Same as query. Arrow version. The result arrow is not injected by local projections.

queryMaybe :: (MonadQualify ConfigureQuery m, MonadQuery m) => Relation () r -> QueryA m () (Projection Flat (Maybe r))

Same as queryMaybe. Arrow version. The result arrow is not injected by any local projections.

query' :: (MonadQualify ConfigureQuery m, MonadQuery m) => Relation p r -> QueryA m () (PlaceHolders p, Projection Flat r)

Same as query'. Arrow version. The result arrow is not injected by any local projections.

queryMaybe' :: (MonadQualify ConfigureQuery m, MonadQuery m) => Relation p r -> QueryA m () (PlaceHolders p, Projection Flat (Maybe r))

Same as queryMaybe'. Arrow version. The result arrow is not injected by any local projections.

queryList :: MonadQualify ConfigureQuery m => (Projection c a -> Relation () r) -> QueryA m (Projection c a) (ListProjection (Projection c) r)

Same as queryList. Arrow version. The result arrow is designed to be injected by local projections.

queryList' :: MonadQualify ConfigureQuery m => (Projection c a -> Relation p r) -> QueryA m (Projection c a) (PlaceHolders p, ListProjection (Projection c) r)

Same as queryList'. Arrow version. The result arrow is designed to be injected by local projections.

queryExists :: MonadQualify ConfigureQuery m => (Projection c a -> Relation () r) -> QueryA m (Projection c a) (ListProjection (Projection Exists) r)

Same as queryList to pass this result to exists operator. Arrow version. The result arrow is designed to be injected by local projections.

queryExists' :: MonadQualify ConfigureQuery m => (Projection c a -> Relation p r) -> QueryA m (Projection c a) (PlaceHolders p, ListProjection (Projection Exists) r)

Same as queryList' to pass this result to exists operator. Arrow version. The result arrow is designed to be injected by local projections.

queryListU :: MonadQualify ConfigureQuery m => Relation () r -> QueryA m () (ListProjection (Projection c) r)

Same as queryList. Arrow version. Useful for no reference cases to local projections.

queryListU' :: MonadQualify ConfigureQuery m => Relation p r -> QueryA m () (PlaceHolders p, ListProjection (Projection c) r)

Same as queryList'. Arrow version. Useful for no reference cases to local projections.

queryScalar :: (MonadQualify ConfigureQuery m, ScalarDegree r) => (Projection c a -> UniqueRelation () c r) -> QueryA m (Projection c a) (Projection c (Maybe r))

Same as queryScalar. Arrow version. The result arrow is designed to be injected by any local projection.

queryScalar' :: (MonadQualify ConfigureQuery m, ScalarDegree r) => (Projection c a -> UniqueRelation p c r) -> QueryA m (Projection c a) (PlaceHolders p, Projection c (Maybe r))

Same as queryScalar'. Arrow version. The result arrow is designed to be injected by any local projection.

queryScalarU :: (MonadQualify ConfigureQuery m, ScalarDegree r) => UniqueRelation () c r -> QueryA m () (Projection c (Maybe r))

Same as queryScalar. Arrow version. Useful for no reference cases to local projections.

queryScalarU' :: (MonadQualify ConfigureQuery m, ScalarDegree r) => UniqueRelation p c r -> QueryA m () (PlaceHolders p, Projection c (Maybe r))

Same as queryScalar'. Arrow version. Useful for no reference cases to local projections.

uniqueQuery' :: UniqueRelation p c r -> QueryA QueryUnique () (PlaceHolders p, Projection c r)

Same as uniqueQuery'. Arrow version. The result arrow is not injected by local projections.

uniqueQueryMaybe' :: UniqueRelation p c r -> QueryA QueryUnique () (PlaceHolders p, Projection c (Maybe r))

Same as uniqueQueryMaybe'. Arrow version. The result arrow is not injected by local projections.

on :: MonadQuery m => QueryA m (Projection Flat (Maybe Bool)) ()

Same as on. Arrow version. The result arrow is designed to be injected by local conditional flat-projections.

wheres :: MonadRestrict Flat m => QueryA m (Projection Flat (Maybe Bool)) ()

Same as wheres. Arrow version. The result arrow is designed to be injected by local conditional flat-projections.

having :: MonadRestrict Aggregated m => QueryA m (Projection Aggregated (Maybe Bool)) ()

Same as having. Arrow version. The result arrow is designed to be injected by local conditional aggregated-projections.

groupBy :: MonadAggregate m => QueryA m (Projection Flat r) (Projection Aggregated r)

Same as groupBy. Arrow version. The result arrow is designed to be injected by local flat-projections.

placeholder :: (PersistableWidth t, SqlProjectable p, Monad m) => QueryA m (QueryA m (p t) a) (PlaceHolders t, a)

Same as placeholder. Arrow version. The result arrow is designed to be injected by locally built arrow using placeholders.

relation :: QuerySimple () (Projection Flat r) -> Relation () r

Same as relation. Finalize query-building arrow instead of query-building monad.

relation' :: QuerySimple () (PlaceHolders p, Projection Flat r) -> Relation p r

Same as relation'. Finalize query-building arrow instead of query-building monad.

aggregateRelation :: QueryAggregate () (Projection Aggregated r) -> Relation () r

Same as aggregateRelation. Finalize query-building arrow instead of query-building monad.

aggregateRelation' :: QueryAggregate () (PlaceHolders p, Projection Aggregated r) -> Relation p r

Same as aggregateRelation'. Finalize query-building arrow instead of query-building monad.

uniqueRelation' :: QueryUnique () (PlaceHolders p, Projection c r) -> UniqueRelation p c r

Same as uniqueRelation'. Finalize query-building arrow instead of query-building monad.

groupBy' :: MonadAggregate m => QueryA m (AggregateKey (Projection Aggregated r)) (Projection Aggregated r)

Same as groupBy'. This arrow is designed to be injected by local AggregateKey.

key :: AggregatingSet (Projection Flat r) (Projection Aggregated (Maybe r))

Same as key. This arrow is designed to be injected by local flat-projections.

key' :: AggregatingSet (AggregateKey a) a

Same as key'. This arrow is designed to be injected by local AggregteKey.

set :: AggregatingSetList (AggregatingSet () a) a

Same as set. This arrow is designed to be injected by locally built AggregtingSet arrow.

bkey :: AggregatingPowerSet (Projection Flat r) (Projection Aggregated (Maybe r))

Same as bkey. This arrow is designed to be injected by local flat-projections.

rollup :: AggregatingPowerSet () a -> AggregateKey a

Same as rollup. Finalize locally built AggregatingPowerSet.

cube :: AggregatingPowerSet () a -> AggregateKey a

Same as cube. Finalize locally built AggregatingPowerSet.

groupingSets :: AggregatingSetList () a -> AggregateKey a

Same as groupingSets. Finalize locally built AggregatingSetList.

orderBy :: Monad m => Order -> Orderings c m (Projection c t) ()

Same as orderBy. The result arrow is designed to be injected by local projections.

asc :: Monad m => Orderings c m (Projection c t) ()

Same as asc. The result arrow is designed to be injected by local projections.

desc :: Monad m => Orderings c m (Projection c t) ()

Same as desc. The result arrow is designed to be injected by local projections.

partitionBy :: Window c (Projection c r) ()

Same as partitionBy. The result arrow is designed to be injected by local projections.

over :: SqlProjectable (Projection c) => Projection OverWindow a -> Window c () () -> Projection c a infix 8

Same as over. Make window function result projection using built Window arrow.

assign :: Monad m => AssignTarget r v -> Assignings r m (Projection Flat v) ()

Make AssignTarget into arrow which is designed to be injected by local projection assignees.

derivedUpdate' :: TableDerivable r => Config -> AssignStatement r (PlaceHolders p) -> Update p

Same as derivedUpdate'. Make Update from assigning statement arrow using configuration.

derivedUpdate :: TableDerivable r => AssignStatement r (PlaceHolders p) -> Update p

Same as derivedUpdate. Make Update from assigning statement arrow.

derivedDelete' :: TableDerivable r => Config -> RestrictedStatement r (PlaceHolders p) -> Delete p

Same as derivedDelete'. Make Update from restrict statement arrow using configuration.

derivedDelete :: TableDerivable r => RestrictedStatement r (PlaceHolders p) -> Delete p

Same as derivedDelete. Make Update from restrict statement arrow.

data QueryA m a b

Arrow to build queries.

Instances

Monad m => Arrow (QueryA m)

Methods

arr :: (b -> c) -> QueryA m b c

first :: QueryA m b c -> QueryA m (b, d) (c, d)

second :: QueryA m b c -> QueryA m (d, b) (d, c)

(***) :: QueryA m b c -> QueryA m b' c' -> QueryA m (b, b') (c, c')

(&&&) :: QueryA m b c -> QueryA m b c' -> QueryA m b (c, c')

Monad m => Category * (QueryA m)

Methods

id :: cat a a

(.) :: cat b c -> cat a b -> cat a c

type QuerySimple = QueryA QuerySimple

Arrow type corresponding to QuerySimple

type QueryAggregate = QueryA QueryAggregate

Arrow type corresponding to QueryAggregate

type QueryUnique = QueryA QueryUnique

Arrow type corresponding to QueryUnique

type AggregatingSet = QueryA AggregatingSet

Arrow type corresponding to AggregatingSet

type AggregatingSetList = QueryA AggregatingSetList

Arrow type corresponding to AggregatingSetList

type AggregatingPowerSet = QueryA AggregatingPowerSet

Arrow type corresponding to AggregatingPowerSet

type Orderings c m = QueryA (Orderings c m)

Arrow type corresponding to Orderings

type Window c = QueryA (Window c)

Arrow type corresponding to Window

type Assignings r m = QueryA (Assignings r m)

Arrow type corresponding to Assignings

type AssignStatement r a = Assignings r Restrict (Projection Flat r) a

Arrow type corresponding to AssignStatement

type RestrictedStatement r a = QueryA Restrict (Projection Flat r) a

Arrow type corresponding to RestrictedStatement