| Copyright | 2014-2017 Kei Hibino |
|---|---|
| License | BSD3 |
| Maintainer | [email protected] |
| Stability | experimental |
| Portability | unknown |
| Safe Haskell | None |
| Language | Haskell2010 |
Database.Relational.Documentation
Description
This module is documentation module for relational-record. The project page of relational-record is http://khibino.github.io/haskell-relational-record/ .
- query :: (MonadQualify ConfigureQuery m, MonadQuery m) => Relation () r -> m (Record Flat r)
- queryMaybe :: (MonadQualify ConfigureQuery m, MonadQuery m) => Relation () r -> m (Record Flat (Maybe r))
- on :: MonadQuery m => Predicate Flat -> m ()
- wheres :: MonadRestrict Flat m => Predicate Flat -> m ()
- groupBy :: MonadAggregate m => forall r. Record Flat r -> m (Record Aggregated r)
- having :: MonadRestrict Aggregated m => Predicate Aggregated -> m ()
- distinct :: MonadQuery m => m ()
- all' :: MonadQuery m => m ()
- (<-#) :: Monad m => AssignTarget r v -> Record Flat v -> Assignings r m ()
- inner :: Relation () a -> Relation () b -> [JoinRestriction a b] -> Relation () (a, b)
- left :: Relation () a -> Relation () b -> [JoinRestriction a (Maybe b)] -> Relation () (a, Maybe b)
- right :: Relation () a -> Relation () b -> [JoinRestriction (Maybe a) b] -> Relation () (Maybe a, b)
- full :: Relation () a -> Relation () b -> [JoinRestriction (Maybe a) (Maybe b)] -> Relation () (Maybe a, Maybe b)
- on' :: ([JoinRestriction a b] -> Relation pc (a, b)) -> [JoinRestriction a b] -> Relation pc (a, b)
- type JoinRestriction a b = Record Flat a -> Record Flat b -> Predicate Flat
- data Relation p r :: * -> * -> *
- relation :: QuerySimple (Record Flat r) -> Relation () r
- aggregateRelation :: QueryAggregate (Record Aggregated r) -> Relation () r
- data UpdateTarget p r :: * -> * -> *
- updateTarget :: AssignStatement r () -> UpdateTarget () r
- data Restriction p r :: * -> * -> *
- restriction :: RestrictedStatement r () -> Restriction () r
- data Record c t :: * -> * -> *
- data Flat :: *
- data Aggregated :: *
- data Exists :: *
- data OverWindow :: *
- data Pi r0 r1 :: * -> * -> *
- (!) :: PersistableWidth a => Record c a -> Pi a b -> Record c b
- (<.>) :: Pi a b -> Pi b c -> Pi a c
- class ShowConstantTermsSQL a
- value :: (ShowConstantTermsSQL t, OperatorContext c) => t -> Record c t
- values :: (ShowConstantTermsSQL t, OperatorContext c) => [t] -> RecordList (Record c) t
- (.=.) :: OperatorContext c => Record c ft -> Record c ft -> Record c (Maybe Bool)
- (.<.) :: OperatorContext c => Record c ft -> Record c ft -> Record c (Maybe Bool)
- (.<=.) :: OperatorContext c => Record c ft -> Record c ft -> Record c (Maybe Bool)
- (.>.) :: OperatorContext c => Record c ft -> Record c ft -> Record c (Maybe Bool)
- (.>=.) :: OperatorContext c => Record c ft -> Record c ft -> Record c (Maybe Bool)
- (.<>.) :: OperatorContext c => Record c ft -> Record c ft -> Record c (Maybe Bool)
- and' :: OperatorContext c => Record c (Maybe Bool) -> Record c (Maybe Bool) -> Record c (Maybe Bool)
- or' :: OperatorContext c => Record c (Maybe Bool) -> Record c (Maybe Bool) -> Record c (Maybe Bool)
- in' :: OperatorContext c => Record c t -> RecordList (Record c) t -> Record c (Maybe Bool)
- (.||.) :: OperatorContext c => Record c a -> Record c a -> Record c a
- like :: (OperatorContext c, IsString a, ShowConstantTermsSQL a) => Record c a -> a -> Record c (Maybe Bool)
- like' :: (OperatorContext c, IsString a) => Record c a -> Record c a -> Record c (Maybe Bool)
- (.+.) :: (OperatorContext c, Num a) => Record c a -> Record c a -> Record c a
- (.-.) :: (OperatorContext c, Num a) => Record c a -> Record c a -> Record c a
- (.*.) :: (OperatorContext c, Num a) => Record c a -> Record c a -> Record c a
- (./.) :: (OperatorContext c, Num a) => Record c a -> Record c a -> Record c a
- isNothing :: (OperatorContext c, HasColumnConstraint NotNull r) => Record c (Maybe r) -> Predicate c
- isJust :: (OperatorContext c, HasColumnConstraint NotNull r) => Record c (Maybe r) -> Predicate c
- fromMaybe :: (OperatorContext c, HasColumnConstraint NotNull r) => Record c r -> Record c (Maybe r) -> Record c r
- not' :: OperatorContext c => Record c (Maybe Bool) -> Record c (Maybe Bool)
- exists :: OperatorContext c => RecordList (Record Exists) r -> Record c (Maybe Bool)
- negate' :: (OperatorContext c, Num a) => Record c a -> Record c a
- fromIntegral' :: (SqlContext c, Integral a, Num b) => Record c a -> Record c b
- showNum :: (SqlContext c, Num a, IsString b) => Record c a -> Record c b
- casesOrElse :: OperatorContext c => [(Predicate c, Record c a)] -> Record c a -> Record c a
- case' :: OperatorContext c => Record c a -> [(Record c a, Record c b)] -> Record c b -> Record c b
- count :: (Integral b, AggregatedContext ac, SqlContext ac) => Record Flat a -> Record ac b
- sum' :: (Num a, AggregatedContext ac, SqlContext ac) => Record Flat a -> Record ac (Maybe a)
- avg :: (Num a, Fractional b, AggregatedContext ac, SqlContext ac) => Record Flat a -> Record ac (Maybe b)
- max' :: (Ord a, AggregatedContext ac, SqlContext ac) => Record Flat a -> Record ac (Maybe a)
- min' :: (Ord a, AggregatedContext ac, SqlContext ac) => Record Flat a -> Record ac (Maybe a)
- every :: (AggregatedContext ac, SqlContext ac) => Predicate Flat -> Record ac (Maybe Bool)
- any' :: (AggregatedContext ac, SqlContext ac) => Predicate Flat -> Record ac (Maybe Bool)
- some' :: (AggregatedContext ac, SqlContext ac) => Predicate Flat -> Record ac (Maybe Bool)
- over :: SqlContext c => Record OverWindow a -> Window c () -> Record c a
- rank :: Integral a => Record OverWindow a
- denseRank :: Integral a => Record OverWindow a
- rowNumber :: Integral a => Record OverWindow a
- percentRank :: Record OverWindow Double
- cumeDist :: Record OverWindow Double
- union :: Relation () a -> Relation () a -> Relation () a
- except :: Relation () a -> Relation () a -> Relation () a
- intersect :: Relation () a -> Relation () a -> Relation () a
- just :: ProjectableMaybe p => forall a. p a -> p (Maybe a)
- flattenMaybe :: ProjectableMaybe p => forall a. p (Maybe (Maybe a)) -> p (Maybe a)
- (?!) :: PersistableWidth a => Record c (Maybe a) -> Pi a b -> Record c (Maybe b)
- (?!?) :: PersistableWidth a => Record c (Maybe a) -> Pi a (Maybe b) -> Record c (Maybe b)
- (<?.>) :: Pi a (Maybe b) -> Pi b c -> Pi a (Maybe c)
- (<?.?>) :: Pi a (Maybe b) -> Pi b (Maybe c) -> Pi a (Maybe c)
- (?+?) :: (OperatorContext c, Num a) => Record c (Maybe a) -> Record c (Maybe a) -> Record c (Maybe a)
- negateMaybe :: (OperatorContext c, Num a) => Record c (Maybe a) -> Record c (Maybe a)
- sumMaybe :: (Num a, AggregatedContext ac, SqlContext ac) => Record Flat (Maybe a) -> Record ac (Maybe a)
- placeholder :: (PersistableWidth t, SqlContext c, Monad m) => (Record c t -> m a) -> m (PlaceHolders t, a)
- query' :: MonadQuery m => forall p r. Relation p r -> m (PlaceHolders p, Record Flat r)
- left' :: Relation pa a -> Relation pb b -> [JoinRestriction a (Maybe b)] -> Relation (pa, pb) (a, Maybe b)
- relation' :: SimpleQuery p r -> Relation p r
- updateTarget' :: AssignStatement r (PlaceHolders p) -> UpdateTarget p r
- restriction' :: RestrictedStatement r (PlaceHolders p) -> Restriction p r
- union' :: Relation p a -> Relation q a -> Relation (p, q) a
- class ProductConstructor c
- class ProductIsoFunctor f where
- class ProductIsoFunctor f => ProductIsoApplicative f where
- (><) :: ProductIsoApplicative p => p a -> p b -> p (a, b)
- relationalQuery :: Relation p r -> Query p r
- typedInsert :: PersistableWidth r => Table r -> Pi r r' -> Insert r'
- typedInsertQuery :: Table r -> Pi r r' -> Relation p r' -> InsertQuery p
- typedUpdate :: Table r -> UpdateTarget p r -> Update p
- typedDelete :: Table r -> Restriction p r -> Delete p
- typedKeyUpdate :: Table a -> Pi a p -> KeyUpdate p a
- derivedInsert :: (PersistableWidth r, TableDerivable r) => Pi r r' -> Insert r'
- derivedInsertQuery :: TableDerivable r => Pi r r' -> Relation p r' -> InsertQuery p
- derivedUpdate :: TableDerivable r => AssignStatement r (PlaceHolders p) -> Update p
- derivedDelete :: TableDerivable r => RestrictedStatement r (PlaceHolders p) -> Delete p
- class FromSql q a
- class PersistableWidth a => ToSql q a
- data RecordFromSql q a :: * -> * -> *
- data RecordToSql q a :: * -> * -> *
- prepareNoFetch :: (UntypeableNoFetch s, IConnection conn) => conn -> s p -> IO (PreparedStatement p ())
- bind :: ToSql SqlValue p => PreparedStatement p a -> p -> BoundStatement a
- execute :: BoundStatement a -> IO (ExecutedStatement a)
- executeNoFetch :: BoundStatement () -> IO Integer
- prepareQuery :: IConnection conn => conn -> Query p a -> IO (PreparedQuery p a)
- fetch :: FromSql SqlValue a => ExecutedStatement a -> IO (Maybe a)
- runQuery :: (IConnection conn, ToSql SqlValue p, FromSql SqlValue a) => conn -> Query p a -> p -> IO [a]
- runQuery' :: (IConnection conn, ToSql SqlValue p, FromSql SqlValue a) => conn -> Query p a -> p -> IO [a]
- prepareInsert :: IConnection conn => conn -> Insert a -> IO (PreparedInsert a)
- runInsert :: (IConnection conn, ToSql SqlValue a) => conn -> Insert a -> a -> IO Integer
- prepareInsertQuery :: IConnection conn => conn -> InsertQuery p -> IO (PreparedInsertQuery p)
- runInsertQuery :: (IConnection conn, ToSql SqlValue p) => conn -> InsertQuery p -> p -> IO Integer
- prepareUpdate :: IConnection conn => conn -> Update p -> IO (PreparedUpdate p)
- runUpdate :: (IConnection conn, ToSql SqlValue p) => conn -> Update p -> p -> IO Integer
- prepareDelete :: IConnection conn => conn -> Delete p -> IO (PreparedDelete p)
- runDelete :: (IConnection conn, ToSql SqlValue p) => conn -> Delete p -> p -> IO Integer
- prepareKeyUpdate :: IConnection conn => conn -> KeyUpdate p a -> IO (PreparedKeyUpdate p a)
- bindKeyUpdate :: ToSql SqlValue a => PreparedKeyUpdate p a -> a -> BoundStatement ()
- runKeyUpdate :: (IConnection conn, ToSql SqlValue a) => conn -> KeyUpdate p a -> a -> IO Integer
Concepts
User interface of Relational Record has main two part of modules.
Database.Relational- Relational Query Building DSL
Database.Record and Database.HDBC.Record- Database Operation Actions
Relational Query Building DSL
Relational Query (Database.Relational) module defines Typed DSL to build complex SQL query.
Monadic Query Context Building
On building query, query structures can be accumulated in monadic context.
Monadic Operators
Some operators are defined to build query structures in monadic context.
query and queryMaybe operators grow query product of monadic context like join operation of SQL.
on operator appends a new condition into recent join product condition.
groupBy operator aggregates flat record value, and can be used only in MonadAggregate context.
wheres and having operators appends a new condition into whole query condition.
having only accepts aggregated record value, and can be used only in MonadRestrict Aggregated context.
distinct operator and all' operator specify SELECT DISTINCT or SELECT ALL, the last specified in monad is used.
<-# operator assigns update target column and record value to build update statement structure.
query :: (MonadQualify ConfigureQuery m, MonadQuery m) => Relation () r -> m (Record Flat r) #
Join sub-query. Query result is not Maybe.
queryMaybe :: (MonadQualify ConfigureQuery m, MonadQuery m) => Relation () r -> m (Record Flat (Maybe r)) #
Join sub-query. Query result is Maybe.
The combinations of query and queryMaybe express
inner joins, left outer joins, right outer joins, and full outer joins.
Here is an example of a right outer join:
outerJoin = relation $ do
e <- queryMaybe employee
d <- query department
on $ e ?! E.deptId' .=. just (d ! D.deptId')
return $ (,) |$| e |*| d
on :: MonadQuery m => Predicate Flat -> m () #
Add restriction to last join. Record type version.
wheres :: MonadRestrict Flat m => Predicate Flat -> m () #
Add restriction to this not aggregated query.
groupBy :: MonadAggregate m => forall r. Record Flat r -> m (Record Aggregated r) #
Add GROUP BY term into context and get aggregated record.
having :: MonadRestrict Aggregated m => Predicate Aggregated -> m () #
Add restriction to this aggregated query. Aggregated Record type version.
distinct :: MonadQuery m => m () #
Specify DISTINCT attribute to query context.
all' :: MonadQuery m => m () #
Specify ALL attribute to query context.
(<-#) :: Monad m => AssignTarget r v -> Record Flat v -> Assignings r m () infix 4 #
Add and assginment.
Direct Join Operators
Not monadic style join is supported by some direct join operators.
inner, left, right, full operators can construct join products directly like SQL.
inner operator is INNER JOIN of SQL, left operator is LEFT OUTER JOIN of SQL, and so on.
on' operator specifies condition of join product.
JoinRestriction is the type of lambda form which expresses condition of join product.
Arguments
| :: Relation () a | Left query to join |
| -> Relation () b | Right query to join |
| -> [JoinRestriction a b] | Join restrictions |
| -> Relation () (a, b) | Result joined relation |
Direct inner join.
Arguments
| :: Relation () a | Left query to join |
| -> Relation () b | Right query to join |
| -> [JoinRestriction a (Maybe b)] | Join restrictions |
| -> Relation () (a, Maybe b) | Result joined relation |
Direct left outer join.
Arguments
| :: Relation () a | Left query to join |
| -> Relation () b | Right query to join |
| -> [JoinRestriction (Maybe a) b] | Join restrictions |
| -> Relation () (Maybe a, b) | Result joined relation |
Direct right outer join.
Arguments
| :: Relation () a | Left query to join |
| -> Relation () b | Right query to join |
| -> [JoinRestriction (Maybe a) (Maybe b)] | Join restrictions |
| -> Relation () (Maybe a, Maybe b) | Result joined relation |
Direct full outer join.
on' :: ([JoinRestriction a b] -> Relation pc (a, b)) -> [JoinRestriction a b] -> Relation pc (a, b) infixl 8 #
Apply restriction for direct join style.
Finalize Context
Several operators are defined to make Relation type with finalizing query monadic context.
relation operator finalizes flat (not aggregated) query monadic context,
and aggregateRelation operator finalizes aggregated query monadic context.
Both operator convert monadic context into Relation type,
and finalized Relation can be reused as joining and sub-querying in another queries.
updateTarget operator finalize monadic context into UpdateTarget type
which can be used as update statement.
restriction operator finalize monadic context into Restriction type
which can be used as delete statement.
data Relation p r :: * -> * -> * #
Relation type with place-holder parameter p and query result type r.
relation :: QuerySimple (Record Flat r) -> Relation () r #
Finalize QuerySimple monad and generate Relation.
aggregateRelation :: QueryAggregate (Record Aggregated r) -> Relation () r #
Finalize QueryAggregate monad and geneate Relation.
data UpdateTarget p r :: * -> * -> * #
UpdateTarget type with place-holder parameter p and projected record type r.
Instances
| TableDerivable r => Show (UpdateTarget p r) | |
updateTarget :: AssignStatement r () -> UpdateTarget () r #
Finalize Target monad and generate UpdateTarget.
data Restriction p r :: * -> * -> * #
Restriction type with place-holder parameter p and projected record type r.
Instances
| TableDerivable r => Show (Restriction p r) | Show where clause. |
restriction :: RestrictedStatement r () -> Restriction () r #
Finalize Restrict monad and generate Restriction.
Record
SQL expression corresponds to Haskell record phantom type in this DSL.
Record Type
Record c a is projected SQL value type corresponding to Haskell record type a with context type c.
Flat is not aggregated query context type,
Aggregated is aggregated query context type,
OverWindow is window function context type, and so on.
Module Database.Relational.Context contains documentation of other context types.
data Aggregated :: * #
Type tag for aggregated query
data OverWindow :: * #
Type tag for window function building
Projection Path
! operator is record value selector using projection path type Pi r0 r1.
Pi r0 r1 is projection path type selecting column type r1 from record type r0.
<.> operator makes composed projection path from two projection paths.
data Pi r0 r1 :: * -> * -> * #
Projection path from type r0 into type r1.
This type also indicate key object which type is r1 for record type r0.
Instances
| ProductIsoFunctor (Pi a) | Map projection path |
| ProductIsoApplicative (Pi a) | Compose projection path |
| Category * Pi | |
| ProductIsoEmpty (Pi a) () | |
| PersistableWidth r0 => Show (Pi r0 r1) | |
Arguments
| :: PersistableWidth a | |
| => Record c a | Source |
| -> Pi a b | Record path |
| -> Record c b | Narrower projected object |
Get narrower record along with projection path.
Record Operators
Some operators are defined to calculate record values.
For example,
value operator lifts from Haskell value into Record corresponding SQL row value,
which conversion is implicitly specified by ShowConstantTermsSQL class.
Generic programming with default signature is available to define instances of ShowConstantTermsSQL.
values operator converts from Haskell list value into RecordList, corresponding SQL set value,
.=. operator is equal compare operation of record value correspond to SQL =,
.+. operator is plus operation of record value correspond to SQL +, and so on.
Module Database.Relational.Projectable contains documentation of other record operators.
class ShowConstantTermsSQL a #
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
value :: (ShowConstantTermsSQL t, OperatorContext c) => t -> Record c t #
Generate record with polymorphic type of SQL constant values from Haskell value.
values :: (ShowConstantTermsSQL t, OperatorContext c) => [t] -> RecordList (Record c) t #
RecordList with polymorphic type of SQL set value from Haskell list.
(.=.) :: OperatorContext c => Record c ft -> Record c ft -> Record c (Maybe Bool) infix 4 #
Compare operator corresponding SQL = .
(.<.) :: OperatorContext c => Record c ft -> Record c ft -> Record c (Maybe Bool) infix 4 #
Compare operator corresponding SQL < .
(.<=.) :: OperatorContext c => Record c ft -> Record c ft -> Record c (Maybe Bool) infix 4 #
Compare operator corresponding SQL <= .
(.>.) :: OperatorContext c => Record c ft -> Record c ft -> Record c (Maybe Bool) infix 4 #
Compare operator corresponding SQL > .
(.>=.) :: OperatorContext c => Record c ft -> Record c ft -> Record c (Maybe Bool) infix 4 #
Compare operator corresponding SQL >= .
(.<>.) :: OperatorContext c => Record c ft -> Record c ft -> Record c (Maybe Bool) infix 4 #
Compare operator corresponding SQL <> .
and' :: OperatorContext c => Record c (Maybe Bool) -> Record c (Maybe Bool) -> Record c (Maybe Bool) infixr 3 #
Logical operator corresponding SQL AND .
or' :: OperatorContext c => Record c (Maybe Bool) -> Record c (Maybe Bool) -> Record c (Maybe Bool) infixr 2 #
Logical operator corresponding SQL OR .
in' :: OperatorContext c => Record c t -> RecordList (Record c) t -> Record c (Maybe Bool) infix 4 #
Binary operator corresponding SQL IN .
(.||.) :: OperatorContext c => Record c a -> Record c a -> Record c a infixl 5 #
Concatinate operator corresponding SQL || .
like :: (OperatorContext c, IsString a, ShowConstantTermsSQL a) => Record c a -> a -> Record c (Maybe Bool) infix 4 #
String-compare operator corresponding SQL LIKE .
like' :: (OperatorContext c, IsString a) => Record c a -> Record c a -> Record c (Maybe Bool) infix 4 #
String-compare operator corresponding SQL LIKE .
(.+.) :: (OperatorContext c, Num a) => Record c a -> Record c a -> Record c a infixl 6 #
Number operator corresponding SQL + .
(.-.) :: (OperatorContext c, Num a) => Record c a -> Record c a -> Record c a infixl 6 #
Number operator corresponding SQL - .
(.*.) :: (OperatorContext c, Num a) => Record c a -> Record c a -> Record c a infixl 7 #
Number operator corresponding SQL * .
(./.) :: (OperatorContext c, Num a) => Record c a -> Record c a -> Record c a infixl 7 #
Number operator corresponding SQL /// .
isNothing :: (OperatorContext c, HasColumnConstraint NotNull r) => Record c (Maybe r) -> Predicate c #
Operator corresponding SQL IS NULL , and extended against record types.
isJust :: (OperatorContext c, HasColumnConstraint NotNull r) => Record c (Maybe r) -> Predicate c #
Operator corresponding SQL NOT (... IS NULL) , and extended against record type.
fromMaybe :: (OperatorContext c, HasColumnConstraint NotNull r) => Record c r -> Record c (Maybe r) -> Record c r #
Operator from maybe type using record extended isNull.
not' :: OperatorContext c => Record c (Maybe Bool) -> Record c (Maybe Bool) #
Logical operator corresponding SQL NOT .
exists :: OperatorContext c => RecordList (Record Exists) r -> Record c (Maybe Bool) #
Logical operator corresponding SQL EXISTS .
negate' :: (OperatorContext c, Num a) => Record c a -> Record c a #
Number negate uni-operator corresponding SQL -.
fromIntegral' :: (SqlContext c, Integral a, Num b) => Record c a -> Record c b #
Number fromIntegral uni-operator.
showNum :: (SqlContext c, Num a, IsString b) => Record c a -> Record c b #
Unsafely show number into string-like type in records.
Arguments
| :: OperatorContext c | |
| => [(Predicate c, Record c a)] | Each when clauses |
| -> Record c a | Else result record |
| -> Record c a | Result record |
Same as caseSearch, but you can write like list casesOrElse clause.
Arguments
| :: OperatorContext c | |
| => Record c a | Record value to match |
| -> [(Record c a, Record c b)] | Each when clauses |
| -> Record c b | Else result record |
| -> Record c b | Result record |
Simple case operator correnponding SQL simple CASE. Like, CASE x WHEN v THEN a WHEN w THEN b ... ELSE c END
Aggregate and Window Functions
Typed aggregate function operators are defined. Aggregated value types is distinguished with Flat value types.
For example,
sum' operator is aggregate function of flat (not aggregated) record value
correspond to SQL SUM(...),
rank operator is window function of record value correspond to SQL RANK(), and so on.
To convert window function result into normal record, use the over operator with built Window monad.
Module Database.Relational.Projectable contains documentation of other aggregate function operators and window function operators.
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.
avg :: (Num a, Fractional b, AggregatedContext ac, SqlContext ac) => Record Flat 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.
min' :: (Ord a, AggregatedContext ac, SqlContext ac) => Record Flat 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.
over :: SqlContext c => Record OverWindow a -> Window c () -> Record c a infix 8 #
Operator to make record of window function result using built Window monad.
rank :: Integral a => Record OverWindow a #
RANK() term.
denseRank :: Integral a => Record OverWindow a #
DENSE_RANK() term.
rowNumber :: Integral a => Record OverWindow a #
ROW_NUMBER() term.
percentRank :: Record OverWindow Double #
PERCENT_RANK() term.
cumeDist :: Record OverWindow Double #
CUME_DIST() term.
Set Operators
Several operators are defined to manipulate relation set.
union operator makes union relation set of two relation set correspond to SQL UNION.
except operator makes difference relation set of two relation set correspond to SQL EXCEPT.
intersect operator makes intersection relation set of two relation set correspond to SQL INTERSECT.
intersect :: Relation () a -> Relation () a -> Relation () a infixl 8 #
Intersection of two relations.
Maybe Records
Some operators are provided to manage records with Maybe phantom type.
just operator creates Maybe typed record,
flattenMaybe operator joins nested Maybe typed record.
Maybe type flavor of operators against projection path, record and aggregation are also provided.
For example,
?! operator is maybe flavor of !,
<?.> operator is maybe flavor of <.>.
?!? operator and <?.?> operator join two Maybe phantom functors.
?+? operator is maybe flavor of .+.,
negateMaybe operator is maybe flavor of negate',
sumMaybe operator is maybe flavor of sum'.
Module Database.Relational.Projectable and Database.Relational.ProjectableExtended
contain documentation of other Maybe flavor operators.
just :: ProjectableMaybe p => forall a. p a -> p (Maybe a) #
Cast record phantom type into Maybe.
flattenMaybe :: ProjectableMaybe p => forall a. p (Maybe (Maybe a)) -> p (Maybe a) #
Compose nested Maybe phantom type on record.
(<?.?>) :: Pi a (Maybe b) -> Pi b (Maybe c) -> Pi a (Maybe c) infixl 8 #
Compose projection path. Maybe phantom functors are join-ed like >=>.
(?+?) :: (OperatorContext c, Num a) => Record c (Maybe a) -> Record c (Maybe a) -> Record c (Maybe a) infixl 6 #
Number operator corresponding SQL + .
negateMaybe :: (OperatorContext c, Num a) => Record c (Maybe a) -> Record c (Maybe a) #
Number negate uni-operator corresponding SQL -.
sumMaybe :: (Num a, AggregatedContext ac, SqlContext ac) => Record Flat (Maybe a) -> Record ac (Maybe a) #
Aggregation function SUM.
Placeholders
placeholders operator takes
a lambda-form which argument is Record typed placeholders and its scope is restricted by that lambda-form
and then creates dummy value with Placeholders typed which propagate placeholder type information into Relation layer.
Placeholders' flavor of operators against query operation and set operation are also provided, to realize type safe placeholders.
query', left', relation', updateTarget', restriction', and union'
operator are placeholders' flavor query, left, relation, updateTarget, restriction and union.
Module Database.Relational.Relation and Database.Relational.Effect contains documentation of other placeholders' flavor operators.
placeholder :: (PersistableWidth t, SqlContext c, Monad m) => (Record c t -> m a) -> m (PlaceHolders t, a) #
Provide scoped placeholder and return its parameter object. Monadic version.
query' :: MonadQuery m => forall p r. Relation p r -> m (PlaceHolders p, Record Flat r) #
Join sub-query with place-holder parameter p. query result is not Maybe.
Arguments
| :: Relation pa a | Left query to join |
| -> Relation pb b | Right query to join |
| -> [JoinRestriction a (Maybe b)] | Join restrictions |
| -> Relation (pa, pb) (a, Maybe b) | Result joined relation |
Direct left outer join with place-holder parameters.
relation' :: SimpleQuery p r -> Relation p r #
Finalize QuerySimple monad and generate Relation with place-holder parameter p.
updateTarget' :: AssignStatement r (PlaceHolders p) -> UpdateTarget p r #
Finalize Target monad and generate UpdateTarget with place-holder parameter p.
restriction' :: RestrictedStatement r (PlaceHolders p) -> Restriction p r #
Finalize Restrict monad and generate Restriction with place-holder parameter p
union' :: Relation p a -> Relation q a -> Relation (p, q) a infixl 7 #
Union of two relations with place-holder parameters.
Record Mapping
Applicative style record mapping is supported, for Record, Pi and PlaceHolders.
|$| operator can be used on ProductIsoFunctor context, and
|*| operator can be used on ProductIsoApplicative context with ProductConstructor,
like Foo |$| record1 |*| record2 |*| record3
, Foo |$| placeholders1 |*| placeholders2 |*| placeholders3, and so on.
>< operator constructs pair result. x >< y is the same as (,) |$| x |*| y.
class ProductConstructor c #
Define product isomorphic inference rule to specify record constructor
Minimal complete definition
class ProductIsoFunctor f where #
Restricted functor on products.
Minimal complete definition
Methods
(|$|) :: ProductConstructor (a -> b) => (a -> b) -> f a -> f b infixl 4 #
Instances
| ProductIsoFunctor (ProductConst a) | |
| Functor f => ProductIsoFunctor (WrappedFunctor f) | |
| ProductIsoFunctor (Pi a) | Map projection path |
| ProductIsoFunctor (WrappedAlter f a) | |
class ProductIsoFunctor f => ProductIsoApplicative f where #
Restricted applicative functor on products.
Instances
| Monoid a => ProductIsoApplicative (ProductConst a) | |
| Applicative f => ProductIsoApplicative (WrappedFunctor f) | |
| ProductIsoApplicative (Pi a) | Compose projection path |
| Alternative f => ProductIsoApplicative (WrappedAlter f a) | |
(><) :: ProductIsoApplicative p => p a -> p b -> p (a, b) infixl 1 #
Binary operator the same as projectZip.
Database Statements
Some functions are defined to expand query structure into flat SQL statements to be used by database operation.
relationalQuery function converts Relation type info flat SQL query like SELECT statement.
typedInsert function converts Pi key type info flat SQL INSERT statement.
typedInsertQuery function converts Pi key type and Relation type info flat SQL INSERT ... SELECT ... statement.
typedUpdate function converts UpdateTarget type into flat SQL UPDATE statement.
typedDelete function converts Restriction into flat SQL DELETE statement.
typedKeyUpdate function converts Pi key type info flat SQL UPDATE statement.
Some handy table type inferred functions are provided,
derivedInsert, derivedInsertQuery, derivedUpdate and derivedDelete.
typedInsert :: PersistableWidth r => Table r -> Pi r r' -> Insert r' #
typedInsertQuery :: Table r -> Pi r r' -> Relation p r' -> InsertQuery p #
Make typed InsertQuery from columns selector Table, Pi and Relation.
typedUpdate :: Table r -> UpdateTarget p r -> Update p #
Make typed Update using defaultConfig, Table and UpdateTarget.
typedDelete :: Table r -> Restriction p r -> Delete p #
Make typed Delete from Table and Restriction.
typedKeyUpdate :: Table a -> Pi a p -> KeyUpdate p a #
derivedInsert :: (PersistableWidth r, TableDerivable r) => Pi r r' -> Insert r' #
Table type inferred Insert.
derivedInsertQuery :: TableDerivable r => Pi r r' -> Relation p r' -> InsertQuery p #
Table type inferred InsertQuery.
derivedUpdate :: TableDerivable r => AssignStatement r (PlaceHolders p) -> Update p #
Make typed Update from defaultConfig, derived table and AssignStatement
derivedDelete :: TableDerivable r => RestrictedStatement r (PlaceHolders p) -> Delete p #
Make typed Delete from defaultConfig, derived table and RestrictContext
Database Operations
Some HDBC actions are defined for database side effects.
Conversion interfaces to communicate with database
Some record conversion interfaces are defined to communicate with database.
The conversions are implicitly specified by FromSql class and ToSql class.
Generic programming with default signature is available to define instances of FromSql and ToSql.
The explicit definitions correnponsing those classes are RecordFromSql and RecordToSql.
FromSql q a is implicit rule to derive RecordFromSql q a record parser function against type a.
Generic programming (https://downloads.haskell.org/~ghc/latest/docs/html/users_guide/glasgow_exts.html#generic-programming)
with default signature is available for FromSql class,
so you can make instance like below:
{-# LANGUAGE DeriveGeneric #-}
import GHC.Generics (Generic)
import Database.HDBC (SqlValue)
--
data Foo = Foo { ... } deriving Generic
instance FromSql SqlValue Foo
Instances
| FromSql q () | Implicit derivation rule of |
| (HasColumnConstraint NotNull a, FromSql q a, PersistableType q) => FromSql q (Maybe a) | Implicit derivation rule of |
class PersistableWidth a => ToSql q a #
ToSql q a is implicit rule to derive RecordToSql q a record printer function for type a.
Generic programming (https://downloads.haskell.org/~ghc/latest/docs/html/users_guide/glasgow_exts.html#generic-programming)
with default signature is available for ToSql class,
so you can make instance like below:
{-# LANGUAGE DeriveGeneric #-}
import GHC.Generics (Generic)
import Database.HDBC (SqlValue)
--
data Foo = Foo { ... } deriving Generic
instance ToSql SqlValue Foo
To make instances of ToSql manually,
ToSql q a and RecordToSql 'q a are composable with monadic context.
When, you have data constructor and objects like below.
data MyRecord = MyRecord Foo Bar Baz
instance ToSql SqlValue Foo where
...
instance ToSql SqlValue Bar where
...
instance ToSql SqlValue Baz where
...
You can get composed ToSql implicit rule like below.
instance ToSql SqlValue MyRecord where
recordToSql =
recordToSql = wrapToSql $ \ (MyRecord x y z) -> do
putRecord x
putRecord y
putRecord z
Instances
| ToSql q () | Implicit derivation rule of |
| (PersistableType q, ToSql q a) => ToSql q (Maybe a) | Implicit derivation rule of |
data RecordFromSql q a :: * -> * -> * #
RecordFromSql q a is data-type wrapping function
to convert from list of database value type (to receive from database) [q] into Haskell type a
This structure is similar to parser.
While running RecordFromSql behavior is the same as non-fail-able parser
which parse list of database value type [q] stream.
So, RecordFromSql q is Monad and Applicative instance like parser monad.
When, you have data constructor and objects like below.
data MyRecord = MyRecord Foo Bar Baz
foo ::RecordFromSqlSqlValue Foo foo = ... bar ::RecordFromSqlSqlValue Bar bar = ... baz ::RecordFromSqlSqlValue Bar baz = ...
You can get composed RecordFromSql like below.
myRecord :: RecordFromSql SqlValue MyRecord myRecord = MyRecord <$> foo <*> bar <*> baz
Instances
| Monad (RecordFromSql q) | |
| Functor (RecordFromSql q) | |
| Applicative (RecordFromSql q) | Derived |
data RecordToSql q a :: * -> * -> * #
RecordToSql q a is data-type wrapping function
to convert from Haskell type a into list of database value type (to send to database) [q].
This structure is similar to printer.
While running RecordToSql behavior is the same as list printer.
which appends list of database value type [q] stream.
Generalized Statement
Actions to manage generalized SQL statements.
prepareNoFetch :: (UntypeableNoFetch s, IConnection conn) => conn -> s p -> IO (PreparedStatement p ()) #
Generalized prepare inferred from UntypeableNoFetch instance.
Arguments
| :: ToSql SqlValue p | |
| => PreparedStatement p a | Prepared query to bind to |
| -> p | Parameter to bind |
| -> BoundStatement a | Result parameter bound statement |
Typed operation to bind parameters. Inferred ToSql is used.
execute :: BoundStatement a -> IO (ExecutedStatement a) #
Use executeBound instead of this.
WARNING! This name will be used for executePrepared function in future release.
executeNoFetch :: BoundStatement () -> IO Integer #
Use executeBoundNoFetch instead of this.
WARNING! This name will be used for runPreparedNoFetch function in future release.
Select
Actions to manage SELECT statements.
runQuery function is lazy-read and runQuery' function is strict version,
please use carefully.
Arguments
| :: IConnection conn | |
| => conn | Database connection |
| -> Query p a | Typed query |
| -> IO (PreparedQuery p a) | Result typed prepared query with parameter type |
Same as prepare.
Arguments
| :: (IConnection conn, ToSql SqlValue p, FromSql SqlValue a) | |
| => conn | Database connection |
| -> Query p a | Query to get record type |
| -> p | Parameter type |
| -> IO [a] | Action to get records |
Prepare SQL, bind parameters, execute statement and lazily fetch all records.
Arguments
| :: (IConnection conn, ToSql SqlValue p, FromSql SqlValue a) | |
| => conn | Database connection |
| -> Query p a | Query to get record type |
| -> p | Parameter type |
| -> IO [a] | Action to get records |
Strict version of runQuery.
Insert Values
Actions to manage INSERT ... VALUES ... statements.
prepareInsert :: IConnection conn => conn -> Insert a -> IO (PreparedInsert a) #
Same as prepare.
runInsert :: (IConnection conn, ToSql SqlValue a) => conn -> Insert a -> a -> IO Integer #
Prepare insert statement, bind parameters, execute statement and get execution result.
Insert Select Results
Actions to manage INSERT ... SELECT ... statements.
prepareInsertQuery :: IConnection conn => conn -> InsertQuery p -> IO (PreparedInsertQuery p) #
Same as prepare.
runInsertQuery :: (IConnection conn, ToSql SqlValue p) => conn -> InsertQuery p -> p -> IO Integer #
Prepare insert statement, bind parameters, execute statement and get execution result.
Update
Actions to manage UPDATE statements.
prepareUpdate :: IConnection conn => conn -> Update p -> IO (PreparedUpdate p) #
Same as prepare.
runUpdate :: (IConnection conn, ToSql SqlValue p) => conn -> Update p -> p -> IO Integer #
Prepare update statement, bind parameters, execute statement and get execution result.
Delete
Actions to manage DELETE statements.
prepareDelete :: IConnection conn => conn -> Delete p -> IO (PreparedDelete p) #
Same as prepare.
runDelete :: (IConnection conn, ToSql SqlValue p) => conn -> Delete p -> p -> IO Integer #
Prepare delete statement, bind parameters, execute statement and get execution result.
Update by Key
Actions to manage UPDATE statements which updates columns other than specified key of the records selected by specified key.
prepareKeyUpdate :: IConnection conn => conn -> KeyUpdate p a -> IO (PreparedKeyUpdate p a) #
Same as prepare.
bindKeyUpdate :: ToSql SqlValue a => PreparedKeyUpdate p a -> a -> BoundStatement () #
Typed operation to bind parameters for PreparedKeyUpdate type.
runKeyUpdate :: (IConnection conn, ToSql SqlValue a) => conn -> KeyUpdate p a -> a -> IO Integer #
Prepare insert statement, bind parameters, execute statement and get execution result.