Database.Esqueleto.Experimental.From.Join

Documentation

data a :& b infixl 2

A left-precedence pair. Pronounced "and". Used to represent expressions that have been joined together.

The precedence behavior can be demonstrated by:

a :& b :& c == ((a :& b) :& c)

See the examples at the beginning of this module to see how this operator is used in JOIN operations.

Constructors

a :& b infixl 2

Instances

(ToFrom a a', ToFrom b b') => DoCrossJoin NotLateral a b (a' :& b')

Defined in Database.Esqueleto.Experimental.From.Join

Methods

doCrossJoin :: Proxy NotLateral -> a -> b -> From (a' :& b')

(ToFrom a a', ToFrom b b', ToMaybe b', ToMaybeT b' ~ mb, HasOnClause rhs (a' :& mb), rhs ~ (b, (a' :& mb) -> SqlExpr (Value Bool))) => DoLeftJoin NotLateral a rhs (a' :& mb)

Defined in Database.Esqueleto.Experimental.From.Join

Methods

doLeftJoin :: Proxy NotLateral -> a -> rhs -> From (a' :& mb)

(ToFrom a a', ToFrom b b', HasOnClause rhs (a' :& b'), rhs ~ (b, (a' :& b') -> SqlExpr (Value Bool))) => DoInnerJoin NotLateral a rhs (a' :& b')

Defined in Database.Esqueleto.Experimental.From.Join

Methods

doInnerJoin :: Proxy NotLateral -> a -> rhs -> From (a' :& b')

(ToFrom a a', SqlSelect b r, ToAlias b, ToAliasReference b) => DoCrossJoin Lateral a (a' -> SqlQuery b) (a' :& b)

Defined in Database.Esqueleto.Experimental.From.Join

Methods

doCrossJoin :: Proxy Lateral -> a -> (a' -> SqlQuery b) -> From (a' :& b)

(ToMaybe a, ToMaybe b) => ToMaybe (a :& b)

Defined in Database.Esqueleto.Experimental.From.Join

Associated Types

type ToMaybeT (a :& b)

Methods

toMaybe :: (a :& b) -> ToMaybeT (a :& b)

(ToAliasReference a, ToAliasReference b) => ToAliasReference (a :& b)

Identical to the tuple instance and provided for convenience.

Since: 3.5.3.0

Defined in Database.Esqueleto.Experimental.From.Join

Methods

toAliasReference :: Ident -> (a :& b) -> SqlQuery (a :& b)

(ToAlias a, ToAlias b) => ToAlias (a :& b)

Identical to the tuple instance and provided for convenience.

Since: 3.5.3.0

Defined in Database.Esqueleto.Experimental.From.Join

Methods

toAlias :: (a :& b) -> SqlQuery (a :& b)

(SqlSelect a ra, SqlSelect b rb) => SqlSelect (a :& b) (ra :& rb)

You may return joined values from a select query - this is identical to the tuple instance, but is provided for convenience.

Since: 3.5.2.0

Defined in Database.Esqueleto.Experimental.From.Join

Methods

sqlSelectCols :: IdentInfo -> (a :& b) -> (Builder, [PersistValue])

sqlSelectColCount :: Proxy (a :& b) -> Int

sqlSelectProcessRow :: [PersistValue] -> Either Text (ra :& rb)

sqlInsertInto :: IdentInfo -> (a :& b) -> (Builder, [PersistValue])

(ToFrom a a', ToFrom b b', ToMaybe a', ToMaybeT a' ~ ma, ToMaybe b', ToMaybeT b' ~ mb, HasOnClause rhs (ma :& mb), ErrorOnLateral b, rhs ~ (b, (ma :& mb) -> SqlExpr (Value Bool))) => ToFrom (FullOuterJoin a rhs) (ma :& mb)

Defined in Database.Esqueleto.Experimental.From.Join

Methods

toFrom :: FullOuterJoin a rhs -> From (ma :& mb)

(ToFrom a a', ToFrom b b', ToMaybe a', ToMaybeT a' ~ ma, HasOnClause rhs (ma :& b'), ErrorOnLateral b, rhs ~ (b, (ma :& b') -> SqlExpr (Value Bool))) => ToFrom (RightOuterJoin a rhs) (ma :& b')

Defined in Database.Esqueleto.Experimental.From.Join

Methods

toFrom :: RightOuterJoin a rhs -> From (ma :& b')

type ToMaybeT (a :& b)

Defined in Database.Esqueleto.Experimental.From.Join

type ToMaybeT (a :& b) = ToMaybeT a :& ToMaybeT b

class ValidOnClause a

Instances

ToFrom a a' => ValidOnClause a

Defined in Database.Esqueleto.Experimental.From.Join

ValidOnClause (a -> SqlQuery b)

Defined in Database.Esqueleto.Experimental.From.Join

on :: ValidOnClause a => a -> (b -> SqlExpr (Value Bool)) -> (a, b -> SqlExpr (Value Bool)) infix 9

An ON clause that describes how two tables are related. This should be used as an infix operator after a JOIN. For example,

select $
from $ table @Person
`innerJoin` table @BlogPost
`on` (\(p :& bP) ->
        p ^. PersonId ==. bP ^. BlogPostAuthorId)

type family ErrorOnLateral a :: Constraint where ...

Equations

ErrorOnLateral (a -> SqlQuery b) = TypeError ('Text "LATERAL can only be used for INNER, LEFT, and CROSS join kinds.")

ErrorOnLateral _ = ()

fromJoin :: Builder -> RawFn -> RawFn -> Maybe (SqlExpr (Value Bool)) -> RawFn

type family HasOnClause actual expected :: Constraint where ...

Equations

HasOnClause (a, b -> SqlExpr (Value Bool)) c = ()

HasOnClause a expected = TypeError (((((('Text "Missing ON clause for join with" :$$: 'ShowType a) :$$: 'Text "") :$$: 'Text "Expected: ") :$$: 'ShowType a) :$$: ('Text "`on` " :<>: 'ShowType (expected -> SqlExpr (Value Bool)))) :$$: 'Text "")

innerJoin :: (ToFrom a a', ToFrom b b', HasOnClause rhs (a' :& b'), rhs ~ (b, (a' :& b') -> SqlExpr (Value Bool))) => a -> rhs -> From (a' :& b') infixl 2

INNER JOIN

Used as an infix operator `innerJoin`

select $
from $ table @Person
`innerJoin` table @BlogPost
`on` (\(p :& bp) ->
        p ^. PersonId ==. bp ^. BlogPostAuthorId)

Since: 3.5.0.0

innerJoinLateral :: (ToFrom a a', HasOnClause rhs (a' :& b), SqlSelect b r, ToAlias b, ToAliasReference b, rhs ~ (a' -> SqlQuery b, (a' :& b) -> SqlExpr (Value Bool))) => a -> rhs -> From (a' :& b) infixl 2

INNER JOIN LATERAL

A Lateral subquery join allows the joined query to reference entities from the left hand side of the join. Discards rows that don't match the on clause

Used as an infix operator `innerJoinLateral`

See example 6

Since: 3.5.0.0

crossJoin :: (ToFrom a a', ToFrom b b') => a -> b -> From (a' :& b') infixl 2

CROSS JOIN

Used as an infix `crossJoin`

select $ do
from $ table @Person
`crossJoin` table @BlogPost

Since: 3.5.0.0

crossJoinLateral :: (ToFrom a a', SqlSelect b r, ToAlias b, ToAliasReference b) => a -> (a' -> SqlQuery b) -> From (a' :& b) infixl 2

CROSS JOIN LATERAL

A Lateral subquery join allows the joined query to reference entities from the left hand side of the join.

Used as an infix operator `crossJoinLateral`

See example 6

Since: 3.5.0.0

leftJoin :: (ToFrom a a', ToFrom b b', ToMaybe b', HasOnClause rhs (a' :& ToMaybeT b'), rhs ~ (b, (a' :& ToMaybeT b') -> SqlExpr (Value Bool))) => a -> rhs -> From (a' :& ToMaybeT b') infixl 2

LEFT OUTER JOIN

Join where the right side may not exist. If the on clause fails then the right side will be NULL'ed Because of this the right side needs to be handled as a Maybe

Used as an infix operator `leftJoin`

select $
from $ table @Person
`leftJoin` table @BlogPost
`on` (\(p :& bp) ->
        p ^. PersonId ==. bp ?. BlogPostAuthorId)

Since: 3.5.0.0

leftJoinLateral :: (ToFrom a a', SqlSelect b r, HasOnClause rhs (a' :& ToMaybeT b), ToAlias b, ToAliasReference b, ToMaybe b, rhs ~ (a' -> SqlQuery b, (a' :& ToMaybeT b) -> SqlExpr (Value Bool))) => a -> rhs -> From (a' :& ToMaybeT b) infixl 2

LEFT OUTER JOIN LATERAL

Lateral join where the right side may not exist. In the case that the query returns nothing or the on clause fails the right side of the join will be NULL'ed Because of this the right side needs to be handled as a Maybe

Used as an infix operator `leftJoinLateral`

See example 6 for how to use LATERAL

Since: 3.5.0.0

rightJoin :: (ToFrom a a', ToFrom b b', ToMaybe a', HasOnClause rhs (ToMaybeT a' :& b'), rhs ~ (b, (ToMaybeT a' :& b') -> SqlExpr (Value Bool))) => a -> rhs -> From (ToMaybeT a' :& b') infixl 2

RIGHT OUTER JOIN

Join where the left side may not exist. If the on clause fails then the left side will be NULL'ed Because of this the left side needs to be handled as a Maybe

Used as an infix operator `rightJoin`

select $
from $ table @Person
`rightJoin` table @BlogPost
`on` (\(p :& bp) ->
        p ?. PersonId ==. bp ^. BlogPostAuthorId)

Since: 3.5.0.0

fullOuterJoin :: (ToFrom a a', ToFrom b b', ToMaybe a', ToMaybe b', HasOnClause rhs (ToMaybeT a' :& ToMaybeT b'), rhs ~ (b, (ToMaybeT a' :& ToMaybeT b') -> SqlExpr (Value Bool))) => a -> rhs -> From (ToMaybeT a' :& ToMaybeT b') infixl 2

FULL OUTER JOIN

Join where both sides of the join may not exist. Because of this the result needs to be handled as a Maybe

Used as an infix operator `fullOuterJoin`

select $
from $ table @Person
`fullOuterJoin` table @BlogPost
`on` (\(p :& bp) ->
        p ?. PersonId ==. bp ?. BlogPostAuthorId)

Since: 3.5.0.0

data Lateral

Instances

(ToFrom a a', ToMaybe b, d ~ (a' :& ToMaybeT b), SqlSelect b r, ToAlias b, ToAliasReference b) => DoLeftJoin Lateral a (a' -> SqlQuery b, d -> SqlExpr (Value Bool)) d

Defined in Database.Esqueleto.Experimental.From.Join

Methods

doLeftJoin :: Proxy Lateral -> a -> (a' -> SqlQuery b, d -> SqlExpr (Value Bool)) -> From d

(ToFrom a a', SqlSelect b r, ToAlias b, ToAliasReference b, d ~ (a' :& b)) => DoInnerJoin Lateral a (a' -> SqlQuery b, d -> SqlExpr (Value Bool)) d

Defined in Database.Esqueleto.Experimental.From.Join

Methods

doInnerJoin :: Proxy Lateral -> a -> (a' -> SqlQuery b, d -> SqlExpr (Value Bool)) -> From d

(ToFrom a a', SqlSelect b r, ToAlias b, ToAliasReference b) => DoCrossJoin Lateral a (a' -> SqlQuery b) (a' :& b)

Defined in Database.Esqueleto.Experimental.From.Join

Methods

doCrossJoin :: Proxy Lateral -> a -> (a' -> SqlQuery b) -> From (a' :& b)

data NotLateral

Instances

(ToFrom a a', ToFrom b b') => DoCrossJoin NotLateral a b (a' :& b')

Defined in Database.Esqueleto.Experimental.From.Join

Methods

doCrossJoin :: Proxy NotLateral -> a -> b -> From (a' :& b')

(ToFrom a a', ToFrom b b', ToMaybe b', ToMaybeT b' ~ mb, HasOnClause rhs (a' :& mb), rhs ~ (b, (a' :& mb) -> SqlExpr (Value Bool))) => DoLeftJoin NotLateral a rhs (a' :& mb)

Defined in Database.Esqueleto.Experimental.From.Join

Methods

doLeftJoin :: Proxy NotLateral -> a -> rhs -> From (a' :& mb)

(ToFrom a a', ToFrom b b', HasOnClause rhs (a' :& b'), rhs ~ (b, (a' :& b') -> SqlExpr (Value Bool))) => DoInnerJoin NotLateral a rhs (a' :& b')

Defined in Database.Esqueleto.Experimental.From.Join

Methods

doInnerJoin :: Proxy NotLateral -> a -> rhs -> From (a' :& b')

type family IsLateral a where ...

Equations

IsLateral (a -> SqlQuery b, c) = Lateral

IsLateral (a -> SqlQuery b) = Lateral

IsLateral a = NotLateral

class DoInnerJoin lateral lhs rhs res | lateral rhs lhs -> res where

Methods

doInnerJoin :: Proxy lateral -> lhs -> rhs -> From res

Instances

(ToFrom a a', ToFrom b b', HasOnClause rhs (a' :& b'), rhs ~ (b, (a' :& b') -> SqlExpr (Value Bool))) => DoInnerJoin NotLateral a rhs (a' :& b')

Defined in Database.Esqueleto.Experimental.From.Join

Methods

doInnerJoin :: Proxy NotLateral -> a -> rhs -> From (a' :& b')

(ToFrom a a', SqlSelect b r, ToAlias b, ToAliasReference b, d ~ (a' :& b)) => DoInnerJoin Lateral a (a' -> SqlQuery b, d -> SqlExpr (Value Bool)) d

Defined in Database.Esqueleto.Experimental.From.Join

Methods

doInnerJoin :: Proxy Lateral -> a -> (a' -> SqlQuery b, d -> SqlExpr (Value Bool)) -> From d

class DoLeftJoin lateral lhs rhs res | lateral rhs lhs -> res where

Methods

doLeftJoin :: Proxy lateral -> lhs -> rhs -> From res

Instances

(ToFrom a a', ToFrom b b', ToMaybe b', ToMaybeT b' ~ mb, HasOnClause rhs (a' :& mb), rhs ~ (b, (a' :& mb) -> SqlExpr (Value Bool))) => DoLeftJoin NotLateral a rhs (a' :& mb)

Defined in Database.Esqueleto.Experimental.From.Join

Methods

doLeftJoin :: Proxy NotLateral -> a -> rhs -> From (a' :& mb)

(ToFrom a a', ToMaybe b, d ~ (a' :& ToMaybeT b), SqlSelect b r, ToAlias b, ToAliasReference b) => DoLeftJoin Lateral a (a' -> SqlQuery b, d -> SqlExpr (Value Bool)) d

Defined in Database.Esqueleto.Experimental.From.Join

Methods

doLeftJoin :: Proxy Lateral -> a -> (a' -> SqlQuery b, d -> SqlExpr (Value Bool)) -> From d

class DoCrossJoin lateral lhs rhs res | lateral lhs rhs -> res where

Methods

doCrossJoin :: Proxy lateral -> lhs -> rhs -> From res

Instances

(ToFrom a a', ToFrom b b') => DoCrossJoin NotLateral a b (a' :& b')

Defined in Database.Esqueleto.Experimental.From.Join

Methods

doCrossJoin :: Proxy NotLateral -> a -> b -> From (a' :& b')

(ToFrom a a', SqlSelect b r, ToAlias b, ToAliasReference b) => DoCrossJoin Lateral a (a' -> SqlQuery b) (a' :& b)

Defined in Database.Esqueleto.Experimental.From.Join

Methods

doCrossJoin :: Proxy Lateral -> a -> (a' -> SqlQuery b) -> From (a' :& b)

Orphan instances

(DoLeftJoin lateral lhs rhs r, lateral ~ IsLateral rhs) => ToFrom (LeftOuterJoin lhs rhs) r

Methods

toFrom :: LeftOuterJoin lhs rhs -> From r

(DoCrossJoin lateral lhs rhs r, IsLateral rhs ~ lateral) => ToFrom (CrossJoin lhs rhs) r

Methods

toFrom :: CrossJoin lhs rhs -> From r

(DoInnerJoin lateral lhs rhs r, lateral ~ IsLateral rhs) => ToFrom (InnerJoin lhs rhs) r

Methods

toFrom :: InnerJoin lhs rhs -> From r

(ToFrom a a', ToFrom b b', ToMaybe a', ToMaybeT a' ~ ma, ToMaybe b', ToMaybeT b' ~ mb, HasOnClause rhs (ma :& mb), ErrorOnLateral b, rhs ~ (b, (ma :& mb) -> SqlExpr (Value Bool))) => ToFrom (FullOuterJoin a rhs) (ma :& mb)

Methods

toFrom :: FullOuterJoin a rhs -> From (ma :& mb)

(ToFrom a a', ToFrom b b', ToMaybe a', ToMaybeT a' ~ ma, HasOnClause rhs (ma :& b'), ErrorOnLateral b, rhs ~ (b, (ma :& b') -> SqlExpr (Value Bool))) => ToFrom (RightOuterJoin a rhs) (ma :& b')

Methods

toFrom :: RightOuterJoin a rhs -> From (ma :& b')