873c511 · squeal · git.iko.soy

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window functions - attempt 3

873c511Eitan Chatav8 years ago

squeal-postgresql/src/Squeal/PostgreSQL/Expression.hs+149

compare with dev

unifiedsplit

@@ -16,11 +16,13 @@ Squeal expressions are the atoms used to build statements.

16 , FlexibleContexts

17 , FlexibleInstances

18 , FunctionalDependencies

19+ , GADTs

19 , GeneralizedNewtypeDeriving

20 , GeneralizedNewtypeDeriving

20 , LambdaCase

21 , LambdaCase

21 , MagicHash

22 , MagicHash

22 , OverloadedStrings

23 , OverloadedStrings

23 , ScopedTypeVariables

24 , ScopedTypeVariables

25+ , StandaloneDeriving

24 , TypeApplications

26 , TypeApplications

25 , TypeFamilies

27 , TypeFamilies

26 , TypeInType

28 , TypeInType

@@ -141,6 +143,18 @@ module Squeal.PostgreSQL.Expression

141 , count, countDistinct

143 , count, countDistinct

142 , every, everyDistinct

144 , every, everyDistinct

143 , max_, maxDistinct, min_, minDistinct

145 , max_, maxDistinct, min_, minDistinct

146+ -- * Window Functions

147+ , WindowDefinition (..)

148+ , partitionBy

149+ , WindowFunction (..)

150+ , rank

151+ , rowNumber

152+ , denseRank

153+ , percentRank

154+ , cumeDist

155+ -- * Sorting

156+ , SortExpression (..)

157+ , OrderBy (..)

144 -- * Types

158 -- * Types

145 , TypeExpression (..)

159 , TypeExpression (..)

146 , PGTyped (..)

160 , PGTyped (..)

@@ -1778,3 +1792,138 @@ instance PGTyped schemas ty

1778instance (KnownNat n, PGTyped schemas ty)

1792instance (KnownNat n, PGTyped schemas ty)

1779 => PGTyped schemas (nullity ('PGfixarray n ty)) where

1793 => PGTyped schemas (nullity ('PGfixarray n ty)) where

1780 pgtype = fixarray @n (pgtype @schemas @ty)

1794 pgtype = fixarray @n (pgtype @schemas @ty)

1795+

1796+{-----------------------------------------

1797+Sorting

1798+-----------------------------------------}

1799+

1800+-- | `SortExpression`s are used by `sortBy` to optionally sort the results

1801+-- of a `Query`. `Asc` or `Desc` set the sort direction of a `NotNull` result

1802+-- column to ascending or descending. Ascending order puts smaller values

1803+-- first, where "smaller" is defined in terms of the `.<` operator. Similarly,

1804+-- descending order is determined with the `.>` operator. `AscNullsFirst`,

1805+-- `AscNullsLast`, `DescNullsFirst` and `DescNullsLast` options are used to

1806+-- determine whether nulls appear before or after non-null values in the sort

1807+-- ordering of a `Null` result column.

1808+data SortExpression commons schemas params grp from where

1809+ Asc

1810+ :: Expression commons schemas params grp from ('NotNull ty)

1811+ -> SortExpression commons schemas params grp from

1812+ Desc

1813+ :: Expression commons schemas params grp from ('NotNull ty)

1814+ -> SortExpression commons schemas params grp from

1815+ AscNullsFirst

1816+ :: Expression commons schemas params grp from ('Null ty)

1817+ -> SortExpression commons schemas params grp from

1818+ AscNullsLast

1819+ :: Expression commons schemas params grp from ('Null ty)

1820+ -> SortExpression commons schemas params grp from

1821+ DescNullsFirst

1822+ :: Expression commons schemas params grp from ('Null ty)

1823+ -> SortExpression commons schemas params grp from

1824+ DescNullsLast

1825+ :: Expression commons schemas params grp from ('Null ty)

1826+ -> SortExpression commons schemas params grp from

1827+deriving instance Show (SortExpression commons schemas params grp from)

1828+

1829+class OrderBy expr where

1830+ orderBy

1831+ :: [SortExpression commons schemas params grp from]

1832+ -> expr commons schemas params grp from

1833+ -> expr commons schemas params grp from

1834+

1835+-- | Render a `SortExpression`.

1836+instance RenderSQL (SortExpression commons schemas params grp from) where

1837+ renderSQL = \case

1838+ Asc expression -> renderSQL expression <+> "ASC"

1839+ Desc expression -> renderSQL expression <+> "DESC"

1840+ AscNullsFirst expression -> renderSQL expression

1841+ <+> "ASC NULLS FIRST"

1842+ DescNullsFirst expression -> renderSQL expression

1843+ <+> "DESC NULLS FIRST"

1844+ AscNullsLast expression -> renderSQL expression <+> "ASC NULLS LAST"

1845+ DescNullsLast expression -> renderSQL expression <+> "DESC NULLS LAST"

1846+

1847+data WindowDefinition commons schemas params grp from where

1848+ WindowDefinition

1849+ :: SListI bys

1850+ => NP (Expression commons schemas params grp from) bys

1851+ -> [SortExpression commons schemas params grp from]

1852+ -> WindowDefinition commons schemas params grp from

1853+

1854+instance OrderBy WindowDefinition where

1855+ orderBy sortsR (WindowDefinition parts sortsL)

1856+ = WindowDefinition parts (sortsL ++ sortsR)

1857+

1858+instance RenderSQL (WindowDefinition commons schemas from grp params) where

1859+ renderSQL (WindowDefinition part ord) =

1860+ renderPartitionByClause part <> renderOrderByClause ord

1861+ where

1862+ renderPartitionByClause = \case

1863+ Nil -> ""

1864+ parts -> "PARTITION" <+> "BY" <+> renderCommaSeparated renderExpression parts

1865+ renderOrderByClause = \case

1866+ [] -> ""

1867+ srts -> " ORDER" <+> "BY"

1868+ <+> commaSeparated (renderSQL <$> srts)

1869+

1870+partitionBy

1871+ :: SListI bys

1872+ => NP (Expression commons schemas params grp from) bys

1873+ -> WindowDefinition commons schemas params grp from

1874+partitionBy bys = WindowDefinition bys []

1875+

1876+newtype WindowFunction

1877+ (commons :: FromType)

1878+ (schemas :: SchemasType)

1879+ (params :: [NullityType])

1880+ (grp :: Grouping)

1881+ (from :: FromType)

1882+ (ty :: NullityType)

1883+ = UnsafeWindowFunction { renderWindowFunction :: ByteString }

1884+ deriving (GHC.Generic,Show,Eq,Ord,NFData)

1885+

1886+instance RenderSQL (WindowFunction commons schemas params grp from ty) where

1887+ renderSQL = renderWindowFunction

1888+

1889+{- | rank of the current row with gaps; same as `rowNumber` of its first peer

1890+>>> :{

1891+let

1892+ expr :: WindowExpression commons schemas params 'Ungrouped '["tab" ::: '["a" ::: ty]] ('NotNull 'PGint8)

1893+ expr = rank `Over` (partitionBy #a)

1894+in

1895+ printSQL expr

1896+:}

1897+rank() OVER (PARTITION BY "a")

1898+-}

1899+rank :: WindowFunction commons schemas from grp params ('NotNull 'PGint8)

1900+rank = UnsafeWindowFunction "rank()"

1901+

1902+{- | number of the current row within its partition, counting from 1

1903+>>> printSQL rowNumber

1904+row_number()

1905+-}

1906+rowNumber :: WindowFunction commons schemas from grp params ('NotNull 'PGint8)

1907+rowNumber = UnsafeWindowFunction "row_number()"

1908+

1909+{- | rank of the current row without gaps; this function counts peer groups

1910+>>> printSQL denseRank

1911+dense_rank()

1912+-}

1913+denseRank :: WindowFunction commons schemas from grp params ('NotNull 'PGint8)

1914+denseRank = UnsafeWindowFunction "dense_rank()"

1915+

1916+{- | relative rank of the current row: (rank - 1) / (total partition rows - 1)

1917+>>> printSQL percentRank

1918+percent_rank()

1919+-}

1920+percentRank :: WindowFunction commons schemas from grp params ('NotNull 'PGfloat8)

1921+percentRank = UnsafeWindowFunction "percent_rank()"

1922+

1923+{- | cumulative distribution: (number of partition rows

1924+preceding or peer with current row) / total partition rows

1925+>>> printSQL cumeDist

1926+cume_dist()

1927+-}

1928+cumeDist :: WindowFunction commons schemas from grp params ('NotNull 'PGfloat8)

1929+cumeDist = UnsafeWindowFunction "cume_dist()"

squeal-postgresql/src/Squeal/PostgreSQL/Query.hs+16−55

@@ -74,7 +74,6 @@ module Squeal.PostgreSQL.Query

74 , where_

75 , groupBy

76 , having

77− , orderBy

78 , limit

77 , limit

79 , offset

78 , offset

80 -- * From Clauses

79 -- * From Clauses

@@ -92,8 +91,6 @@ module Squeal.PostgreSQL.Query

92 , By (..)

91 , By (..)

93 , GroupByClause (..)

92 , GroupByClause (..)

94 , HavingClause (..)

93 , HavingClause (..)

95− -- * Sorting

96− , SortExpression (..)

97 -- * Subquery Expressions

94 -- * Subquery Expressions

98 , in_

95 , in_

99 , rowIn

96 , rowIn

@@ -412,6 +409,11 @@ data Selection commons schemas params grp from row where

412 :: Selection commons schemas params grp from right

409 :: Selection commons schemas params grp from right

413 -> Selection commons schemas params grp from left

410 -> Selection commons schemas params grp from left

414 -> Selection commons schemas params grp from (Join left right)

411 -> Selection commons schemas params grp from (Join left right)

412+ Over

413+ :: SListI row

414+ => NP (Aliased (WindowFunction commons schemas params grp from)) row

415+ -> WindowDefinition commons schemas params grp from

416+ -> Selection commons schemas params grp from row

415instance (KnownSymbol col, row ~ '[col ::: ty])

417instance (KnownSymbol col, row ~ '[col ::: ty])

416 => Aliasable col

418 => Aliasable col

417 (Expression commons schemas params grp from ty)

419 (Expression commons schemas params grp from ty)

@@ -444,6 +446,15 @@ instance RenderSQL (Selection commons schemas params grp from row) where

444 Star -> "*"

446 Star -> "*"

445 DotStar tab -> renderSQL tab <> ".*"

447 DotStar tab -> renderSQL tab <> ".*"

446 Also right left -> renderSQL left <> ", " <> renderSQL right

448 Also right left -> renderSQL left <> ", " <> renderSQL right

449+ Over winFns winDef ->

450+ let

451+ renderOver

452+ :: Aliased (WindowFunction commons schemas params grp from) field

453+ -> ByteString

454+ renderOver winFn = renderAliased renderSQL winFn

455+ <+> "OVER" <+> parenthesized (renderSQL winDef)

456+ in

457+ renderCommaSeparated renderOver winFns

447

458

448-- | the `TableExpression` in the `select` command constructs an intermediate

459-- | the `TableExpression` in the `select` command constructs an intermediate

449-- virtual table by possibly combining tables, views, eliminating rows,

460-- virtual table by possibly combining tables, views, eliminating rows,

@@ -662,13 +673,8 @@ having

662having hv rels = rels

673having hv rels = rels

663 { havingClause = case havingClause rels of Having hvs -> Having (hv:hvs) }

674 { havingClause = case havingClause rels of Having hvs -> Having (hv:hvs) }

664

675

665−-- | An `orderBy` is an endomorphism of `TableExpression`s which appends an

676+instance OrderBy TableExpression where

666−-- ordering to the right of the `orderByClause`.

667−orderBy

668− :: [SortExpression commons schemas params grp from] -- ^ sort expressions

669− -> TableExpression commons schemas params grp from

670− -> TableExpression commons schemas params grp from

671−orderBy srts rels = rels {orderByClause = orderByClause rels ++ srts}

677+ orderBy srts rels = rels {orderByClause = orderByClause rels ++ srts}

672

678

673-- | A `limit` is an endomorphism of `TableExpression`s which adds to the

679-- | A `limit` is an endomorphism of `TableExpression`s which adds to the

674-- `limitClause`.

680-- `limitClause`.

@@ -1035,51 +1041,6 @@ instance RenderSQL (HavingClause commons schemas params grp from) where

1035 Having conditions ->

1041 Having conditions ->

1036 " HAVING" <+> commaSeparated (renderSQL <$> conditions)

1042 " HAVING" <+> commaSeparated (renderSQL <$> conditions)

1037

1043

1038−{-----------------------------------------

1039−Sorting

1040−-----------------------------------------}

1041−

1042−-- | `SortExpression`s are used by `sortBy` to optionally sort the results

1043−-- of a `Query`. `Asc` or `Desc` set the sort direction of a `NotNull` result

1044−-- column to ascending or descending. Ascending order puts smaller values

1045−-- first, where "smaller" is defined in terms of the `.<` operator. Similarly,

1046−-- descending order is determined with the `.>` operator. `AscNullsFirst`,

1047−-- `AscNullsLast`, `DescNullsFirst` and `DescNullsLast` options are used to

1048−-- determine whether nulls appear before or after non-null values in the sort

1049−-- ordering of a `Null` result column.

1050−data SortExpression commons schemas params grp from where

1051− Asc

1052− :: Expression commons schemas params grp from ('NotNull ty)

1053− -> SortExpression commons schemas params grp from

1054− Desc

1055− :: Expression commons schemas params grp from ('NotNull ty)

1056− -> SortExpression commons schemas params grp from

1057− AscNullsFirst

1058− :: Expression commons schemas params grp from ('Null ty)

1059− -> SortExpression commons schemas params grp from

1060− AscNullsLast

1061− :: Expression commons schemas params grp from ('Null ty)

1062− -> SortExpression commons schemas params grp from

1063− DescNullsFirst

1064− :: Expression commons schemas params grp from ('Null ty)

1065− -> SortExpression commons schemas params grp from

1066− DescNullsLast

1067− :: Expression commons schemas params grp from ('Null ty)

1068− -> SortExpression commons schemas params grp from

1069−deriving instance Show (SortExpression commons schemas params grp from)

1070−

1071−-- | Render a `SortExpression`.

1072−instance RenderSQL (SortExpression commons schemas params grp from) where

1073− renderSQL = \case

1074− Asc expression -> renderSQL expression <+> "ASC"

1075− Desc expression -> renderSQL expression <+> "DESC"

1076− AscNullsFirst expression -> renderSQL expression

1077− <+> "ASC NULLS FIRST"

1078− DescNullsFirst expression -> renderSQL expression

1079− <+> "DESC NULLS FIRST"

1080− AscNullsLast expression -> renderSQL expression <+> "ASC NULLS LAST"

1081− DescNullsLast expression -> renderSQL expression <+> "DESC NULLS LAST"

1082−

1083unsafeSubqueryExpression

1044unsafeSubqueryExpression

1084 :: ByteString

1045 :: ByteString

1085 -> Expression commons schemas params grp from ty

1046 -> Expression commons schemas params grp from ty