Database.Relational.Query.Projectable

This module defines operators on various polymorphic projections.

Conversion between individual Projections

expr :: Projection p a -> Expr p a

Project from Projection type into expression type.

Projectable from SQL strings

class SqlProjectable p where

Interface to project SQL terms unsafely.

Methods

unsafeProjectSqlTerms

Arguments

:: [String]

SQL expression strings

-> p t

Result projection object

Unsafely project from SQL expression strings.

Instances

SqlProjectable (Expr p)

Unsafely make Expr from SQL terms.

SqlProjectable (Projection OverWindow)

Unsafely make Projection from SQL terms.

SqlProjectable (Projection Aggregated)

Unsafely make Projection from SQL terms.

SqlProjectable (Projection Flat)

Unsafely make Projection from SQL terms.

unsafeProjectSql :: SqlProjectable p => String -> p t

Unsafely Project single SQL term.

Projections of values

value :: (ShowConstantTermsSQL t, SqlProjectable p) => t -> p t

Generate polymorphic projection of SQL constant values from Haskell value.

valueTrue :: (SqlProjectable p, ProjectableMaybe p) => p (Maybe Bool)

Polymorphic proejction of SQL true value.

valueFalse :: (SqlProjectable p, ProjectableMaybe p) => p (Maybe Bool)

Polymorphic proejction of SQL false value.

values :: (ShowConstantTermsSQL t, SqlProjectable p) => [t] -> ListProjection p t

Polymorphic proejction of SQL set value from Haskell list.

unsafeValueNull :: SqlProjectable p => p (Maybe a)

Polymorphic projection of SQL null value.

Placeholders

data PlaceHolders p

Placeholder parameter type which has real parameter type arguemnt p.

Instances

ProjectableApplicative PlaceHolders

Compose record type PlaceHolders using applicative style.

ProjectableFunctor PlaceHolders

Compose seed of record type PlaceHolders.

ProjectableIdZip PlaceHolders

Zipping except for identity element laws against placeholder parameter type.

ProjectableMaybe PlaceHolders

Control phantom Maybe type in placeholder parameters.

addPlaceHolders :: Functor f => f a -> f (PlaceHolders p, a)

Unsafely add placeholder parameter to queries.

unsafePlaceHolders :: PlaceHolders p

Unsafely get placeholder parameter

placeholder' :: (PersistableWidth t, SqlProjectable p) => (p t -> a) -> (PlaceHolders t, a)

Provide scoped placeholder and return its parameter object.

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

Provide scoped placeholder and return its parameter object. Monadic version.

Projectable into SQL strings

unsafeShowSqlExpr :: Expr p t -> String

Unsafely get SQL term from Expr.

unsafeShowSqlProjection :: Projection c r -> String

Unsafely get SQL term from Proejction.

class ProjectableShowSql p where

Interface to get SQL term from projections.

Methods

unsafeShowSql

Arguments

:: p a

Source projection object

-> String

Result SQL expression string.

Unsafely generate SQL expression string from projection object.

Instances

ProjectableShowSql (Expr p)

Unsafely get SQL term from Expr.

ProjectableShowSql (Projection c)

Unsafely get SQL term from Proejction.

Operators

type SqlBinOp = Keyword -> Keyword -> Keyword

Binary operator type for SQL String.

unsafeBinOp :: (SqlProjectable p, ProjectableShowSql p) => SqlBinOp -> p a -> p b -> p c

Unsafely make projection binary operator from string binary operator.

unsafeUniOp :: (ProjectableShowSql p0, SqlProjectable p1) => (Keyword -> Keyword) -> p0 a -> p1 b

Unsafely make projection unary operator from SQL keyword.

(.=.) :: (SqlProjectable p, ProjectableShowSql p) => p ft -> p ft -> p (Maybe Bool)

Compare operator corresponding SQL = .

(.<.) :: (SqlProjectable p, ProjectableShowSql p) => p ft -> p ft -> p (Maybe Bool)

Compare operator corresponding SQL < .

(.<=.) :: (SqlProjectable p, ProjectableShowSql p) => p ft -> p ft -> p (Maybe Bool)

Compare operator corresponding SQL <= .

(.>.) :: (SqlProjectable p, ProjectableShowSql p) => p ft -> p ft -> p (Maybe Bool)

Compare operator corresponding SQL > .

(.>=.) :: (SqlProjectable p, ProjectableShowSql p) => p ft -> p ft -> p (Maybe Bool)

Compare operator corresponding SQL >= .

(.<>.) :: (SqlProjectable p, ProjectableShowSql p) => p ft -> p ft -> p (Maybe Bool)

Compare operator corresponding SQL <> .

casesOrElse

Arguments

:: (SqlProjectable p, ProjectableShowSql p)

=> [(p (Maybe Bool), p a)]

Each when clauses

-> p a

Else result projection

-> p a

Result projection

Same as caseSearch, but you can write like list casesOrElse clause.

casesOrElse'

Arguments

:: (SqlProjectable p, ProjectableShowSql p)

=> (p a, [(p a, p b)])

Projection value to match and each when clauses list

-> p b

Else result projection

-> p b

Result projection

Uncurry version of case', and you can write like ... casesOrElse' clause.

caseSearch

Arguments

:: (SqlProjectable p, ProjectableShowSql p)

=> [(p (Maybe Bool), p a)]

Each when clauses

-> p a

Else result projection

-> p a

Result projection

Search case operator correnponding SQL search CASE. Like, CASE WHEN p0 THEN a WHEN p1 THEN b ... ELSE c END

caseSearchMaybe

Arguments

:: (ProjectableShowSql p, SqlProjectable p)

=> [(p (Maybe Bool), p (Maybe a))]

Each when clauses

-> p (Maybe a)

Result projection

Null default version of caseSearch.

case'

Arguments

:: (SqlProjectable p, ProjectableShowSql p)

=> p a

Projection value to match

-> [(p a, p b)]

Each when clauses

-> p b

Else result projection

-> p b

Result projection

Simple case operator correnponding SQL simple CASE. Like, CASE x WHEN v THEN a WHEN w THEN b ... ELSE c END

caseMaybe

Arguments

:: (SqlProjectable p, ProjectableShowSql p, ProjectableMaybe p)

=> p a

Projection value to match

-> [(p a, p (Maybe b))]

Each when clauses

-> p (Maybe b)

Result projection

Null default version of case'.

in' :: (SqlProjectable p, ProjectableShowSql p) => p t -> ListProjection p t -> p (Maybe Bool)

Binary operator corresponding SQL IN .

and' :: (SqlProjectable p, ProjectableShowSql p) => p ft -> p ft -> p (Maybe Bool)

Logical operator corresponding SQL AND .

or' :: (SqlProjectable p, ProjectableShowSql p) => p ft -> p ft -> p (Maybe Bool)

Logical operator corresponding SQL OR .

isNothing :: (SqlProjectable (Projection c), ProjectableShowSql (Projection c), HasColumnConstraint NotNull r) => Projection c (Maybe r) -> Projection c (Maybe Bool)

Operator corresponding SQL IS NULL , and extended against record types.

isJust :: (SqlProjectable (Projection c), ProjectableShowSql (Projection c), HasColumnConstraint NotNull r) => Projection c (Maybe r) -> Projection c (Maybe Bool)

Operator corresponding SQL NOT (... IS NULL) , and extended against record type.

fromMaybe :: (SqlProjectable (Projection c), ProjectableShowSql (Projection c), HasColumnConstraint NotNull r) => Projection c r -> Projection c (Maybe r) -> Projection c r

Operator from maybe type using record extended isNull.

fromMaybe' :: (SqlProjectable (Projection c), ProjectableShowSql (Projection c), HasColumnConstraint NotNull r) => Projection c r -> Projection c (Maybe r) -> Projection c r

Deprecated: Use fromMaybe instead of this.

Deprecated. Operator from maybe type using record extended isNull.

not' :: (SqlProjectable p, ProjectableShowSql p) => p (Maybe Bool) -> p (Maybe Bool)

Logical operator corresponding SQL NOT .

exists :: (SqlProjectable p, ProjectableShowSql p) => ListProjection (Projection Exists) r -> p (Maybe Bool)

Logical operator corresponding SQL EXISTS .

(.||.) :: (SqlProjectable p, ProjectableShowSql p, IsString a) => p a -> p a -> p a

Concatinate operator corresponding SQL || .

(?||?) :: (SqlProjectable p, ProjectableShowSql p, IsString a) => p (Maybe a) -> p (Maybe a) -> p (Maybe a)

Concatinate operator corresponding SQL || . Maybe type version.

(.+.) :: (SqlProjectable p, ProjectableShowSql p, Num a) => p a -> p a -> p a

Number operator corresponding SQL + .

(.-.) :: (SqlProjectable p, ProjectableShowSql p, Num a) => p a -> p a -> p a

Number operator corresponding SQL - .

(./.) :: (SqlProjectable p, ProjectableShowSql p, Num a) => p a -> p a -> p a

Number operator corresponding SQL / .

(.*.) :: (SqlProjectable p, ProjectableShowSql p, Num a) => p a -> p a -> p a

Number operator corresponding SQL * .

negate' :: (SqlProjectable p, ProjectableShowSql p, Num a) => p a -> p a

Number negate uni-operator corresponding SQL -.

fromIntegral' :: (SqlProjectable p, ProjectableShowSql p, Integral a, Num b) => p a -> p b

Number fromIntegral uni-operator.

showNum :: (SqlProjectable p, ProjectableShowSql p, Num a, IsString b) => p a -> p b

Unsafely show number into string-like type in projections.

(?+?) :: (SqlProjectable p, ProjectableShowSql p, Num a) => p (Maybe a) -> p (Maybe a) -> p (Maybe a)

Number operator corresponding SQL + .

(?-?) :: (SqlProjectable p, ProjectableShowSql p, Num a) => p (Maybe a) -> p (Maybe a) -> p (Maybe a)

Number operator corresponding SQL - .

(?/?) :: (SqlProjectable p, ProjectableShowSql p, Num a) => p (Maybe a) -> p (Maybe a) -> p (Maybe a)

Number operator corresponding SQL / .

(?*?) :: (SqlProjectable p, ProjectableShowSql p, Num a) => p (Maybe a) -> p (Maybe a) -> p (Maybe a)

Number operator corresponding SQL * .

negateMaybe :: (SqlProjectable p, ProjectableShowSql p, Num a) => p (Maybe a) -> p (Maybe a)

Number negate uni-operator corresponding SQL -.

fromIntegralMaybe :: (SqlProjectable p, ProjectableShowSql p, Integral a, Num b) => p (Maybe a) -> p (Maybe b)

Number fromIntegral uni-operator.

showNumMaybe :: (SqlProjectable p, ProjectableShowSql p, Num a, IsString b) => p (Maybe a) -> p (Maybe b)

Unsafely show number into string-like type in projections.

Terms for Window function types

rank :: Projection OverWindow Int64

RANK() term.

denseRank :: Projection OverWindow Int64

DENSE_RANK() term.

rowNumber :: Projection OverWindow Int64

ROW_NUMBER() term.

percentRank :: Projection OverWindow Double

PERCENT_RANK() term.

cumeDist :: Projection OverWindow Double

CUME_DIST() term.

dense_rank :: Projection OverWindow Int64

Deprecated: Use denseRank instead of this.

DENSE_RANK() term.

row_number :: Projection OverWindow Int64

Deprecated: Use rowNumber instead of this.

ROW_NUMBER() term.

percent_rank :: Projection OverWindow Double

Deprecated: Use percentRank instead of this.

PERCENT_RANK() term.

cume_dist :: Projection OverWindow Double

Deprecated: Use cumeDist instead of this.

CUME_DIST() term.

Zipping projections

projectZip :: ProjectableApplicative p => p a -> p b -> p (a, b)

Zipping projections.

(><) :: ProjectableApplicative p => p a -> p b -> p (a, b)

Binary operator the same as projectZip.

class ProjectableApplicative p => ProjectableIdZip p where

Zipping except for identity element laws.

Methods

leftId :: p ((), a) -> p a

rightId :: p (a, ()) -> p a

Instances

ProjectableIdZip PlaceHolders

Zipping except for identity element laws against placeholder parameter type.

Maybe type projecitoins

class ProjectableMaybe p where

Interface to control Maybe of phantom type in projections.

Methods

just :: p a -> p (Maybe a)

Cast projection phantom type into Maybe.

flattenMaybe :: p (Maybe (Maybe a)) -> p (Maybe a)

Compose nested Maybe phantom type on projection.

Instances

ProjectableMaybe PlaceHolders

Control phantom Maybe type in placeholder parameters.

ProjectableMaybe (Expr p)

Control phantom Maybe type in SQL expression type Expr.

ProjectableMaybe (Projection c)

Control phantom Maybe type in projection type Projection.

ProjectableFunctor and ProjectableApplicative

class ProjectableFunctor p where

Weaken functor on projections.

Methods

(|$|) :: ProductConstructor (a -> b) => (a -> b) -> p a -> p b

Method like fmap.

Instances

ProjectableFunctor PlaceHolders

Compose seed of record type PlaceHolders.

ProjectableFunctor (Pi a)

Compose seed of projection path Pi which has record result type.

ProjectableFunctor (Projection c)

Compose seed of record type Projection.

class ProjectableFunctor p => ProjectableApplicative p where

Weaken applicative functor on projections.

Methods

(|*|) :: p (a -> b) -> p a -> p b

Method like <*>.

Instances

ProjectableApplicative PlaceHolders

Compose record type PlaceHolders using applicative style.

ProjectableApplicative (Pi a)

Compose projection path Pi which has record result type using applicative style.

ProjectableApplicative (Projection c)

Compose record type Projection using applicative style.

ipfmap :: (ProjectableFunctor p, ProductConstructor (a -> b)) => p a -> p b

Same as |$| other than using infered record constructor.