Copyright	(c) Eitan Chatav 2019
Maintainer	eitan@morphism.tech
Stability	experimental
Safe Haskell	None
Language	Haskell2010

Squeal.PostgreSQL.Session.Connection

Description

database connections

Synopsis

data Connection
connectdb :: forall (db :: SchemasType) io. MonadIO io => ByteString -> io (K Connection db)
finish :: MonadIO io => K Connection db -> io ()
lowerConnection :: K Connection (schema ': db) -> K Connection db
newtype K a (b :: k) :: forall k. Type -> k -> Type = K a
unK :: K a b -> a

Documentation

data Connection #

Connection encapsulates a connection to the backend.

Instances

Eq Connection
Instance details Defined in Database.PostgreSQL.LibPQ.Internal Methods (==) :: Connection -> Connection -> Bool # (/=) :: Connection -> Connection -> Bool #

connectdb Source #

Arguments

:: forall (db :: SchemasType). MonadIO io
=> ByteString	conninfo
-> io (K Connection db)

Makes a new connection to the database server.

This function opens a new database connection using the parameters taken from the string conninfo.

The passed string can be empty to use all default parameters, or it can contain one or more parameter settings separated by whitespace. Each parameter setting is in the form keyword = value. Spaces around the equal sign are optional. To write an empty value or a value containing spaces, surround it with single quotes, e.g., keyword = 'a value'. Single quotes and backslashes within the value must be escaped with a backslash, i.e., ' and .

To specify the schema you wish to connect with, use type application.

>>> :set -XDataKinds
>>> :set -XPolyKinds
>>> :set -XTypeOperators
>>> type DB = '["public" ::: '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'Null 'PGint2])]]
>>> :set -XTypeApplications
>>> :set -XOverloadedStrings
>>> conn <- connectdb @DB "host=localhost port=5432 dbname=exampledb"

Note that, for now, squeal doesn't offer any protection from connecting with the wrong schema!

finish :: MonadIO io => K Connection db -> io () Source #

Closes the connection to the server.

lowerConnection :: K Connection (schema ': db) -> K Connection db Source #

Safely lowerConnection to a smaller schema.

newtype K a (b :: k) :: forall k. Type -> k -> Type #

The constant type functor.

Like Constant, but kind-polymorphic in its second argument and with a shorter name.

Constructors

K a

Instances

Eq2 (K :: Type -> Type -> Type)	Since: sop-core-0.2.4.0
Instance details Defined in Data.SOP.BasicFunctors Methods liftEq2 :: (a -> b -> Bool) -> (c -> d -> Bool) -> K a c -> K b d -> Bool #
Ord2 (K :: Type -> Type -> Type)	Since: sop-core-0.2.4.0
Instance details Defined in Data.SOP.BasicFunctors Methods liftCompare2 :: (a -> b -> Ordering) -> (c -> d -> Ordering) -> K a c -> K b d -> Ordering #
Read2 (K :: Type -> Type -> Type)	Since: sop-core-0.2.4.0
Instance details Defined in Data.SOP.BasicFunctors Methods liftReadsPrec2 :: (Int -> ReadS a) -> ReadS [a] -> (Int -> ReadS b) -> ReadS [b] -> Int -> ReadS (K a b) # liftReadList2 :: (Int -> ReadS a) -> ReadS [a] -> (Int -> ReadS b) -> ReadS [b] -> ReadS [K a b] # liftReadPrec2 :: ReadPrec a -> ReadPrec [a] -> ReadPrec b -> ReadPrec [b] -> ReadPrec (K a b) # liftReadListPrec2 :: ReadPrec a -> ReadPrec [a] -> ReadPrec b -> ReadPrec [b] -> ReadPrec [K a b] #
Show2 (K :: Type -> Type -> Type)	Since: sop-core-0.2.4.0
Instance details Defined in Data.SOP.BasicFunctors Methods liftShowsPrec2 :: (Int -> a -> ShowS) -> ([a] -> ShowS) -> (Int -> b -> ShowS) -> ([b] -> ShowS) -> Int -> K a b -> ShowS # liftShowList2 :: (Int -> a -> ShowS) -> ([a] -> ShowS) -> (Int -> b -> ShowS) -> ([b] -> ShowS) -> [K a b] -> ShowS #
NFData2 (K :: Type -> Type -> Type)	Since: sop-core-0.2.5.0
Instance details Defined in Data.SOP.BasicFunctors Methods liftRnf2 :: (a -> ()) -> (b -> ()) -> K a b -> () #
Functor (K a :: Type -> Type)
Instance details Defined in Data.SOP.BasicFunctors Methods fmap :: (a0 -> b) -> K a a0 -> K a b # (<$) :: a0 -> K a b -> K a a0 #
Monoid a => Applicative (K a :: Type -> Type)
Instance details Defined in Data.SOP.BasicFunctors Methods pure :: a0 -> K a a0 # (<>) :: K a (a0 -> b) -> K a a0 -> K a b # liftA2 :: (a0 -> b -> c) -> K a a0 -> K a b -> K a c # (>) :: K a a0 -> K a b -> K a b # (<*) :: K a a0 -> K a b -> K a a0 #
Foldable (K a :: Type -> Type)
Instance details Defined in Data.SOP.BasicFunctors Methods fold :: Monoid m => K a m -> m # foldMap :: Monoid m => (a0 -> m) -> K a a0 -> m # foldr :: (a0 -> b -> b) -> b -> K a a0 -> b # foldr' :: (a0 -> b -> b) -> b -> K a a0 -> b # foldl :: (b -> a0 -> b) -> b -> K a a0 -> b # foldl' :: (b -> a0 -> b) -> b -> K a a0 -> b # foldr1 :: (a0 -> a0 -> a0) -> K a a0 -> a0 # foldl1 :: (a0 -> a0 -> a0) -> K a a0 -> a0 # toList :: K a a0 -> [a0] # null :: K a a0 -> Bool # length :: K a a0 -> Int # elem :: Eq a0 => a0 -> K a a0 -> Bool # maximum :: Ord a0 => K a a0 -> a0 # minimum :: Ord a0 => K a a0 -> a0 # sum :: Num a0 => K a a0 -> a0 # product :: Num a0 => K a a0 -> a0 #
Traversable (K a :: Type -> Type)
Instance details Defined in Data.SOP.BasicFunctors Methods traverse :: Applicative f => (a0 -> f b) -> K a a0 -> f (K a b) # sequenceA :: Applicative f => K a (f a0) -> f (K a a0) # mapM :: Monad m => (a0 -> m b) -> K a a0 -> m (K a b) # sequence :: Monad m => K a (m a0) -> m (K a a0) #
Eq a => Eq1 (K a :: Type -> Type)	Since: sop-core-0.2.4.0
Instance details Defined in Data.SOP.BasicFunctors Methods liftEq :: (a0 -> b -> Bool) -> K a a0 -> K a b -> Bool #
Ord a => Ord1 (K a :: Type -> Type)	Since: sop-core-0.2.4.0
Instance details Defined in Data.SOP.BasicFunctors Methods liftCompare :: (a0 -> b -> Ordering) -> K a a0 -> K a b -> Ordering #
Read a => Read1 (K a :: Type -> Type)	Since: sop-core-0.2.4.0
Instance details Defined in Data.SOP.BasicFunctors Methods liftReadsPrec :: (Int -> ReadS a0) -> ReadS [a0] -> Int -> ReadS (K a a0) # liftReadList :: (Int -> ReadS a0) -> ReadS [a0] -> ReadS [K a a0] # liftReadPrec :: ReadPrec a0 -> ReadPrec [a0] -> ReadPrec (K a a0) # liftReadListPrec :: ReadPrec a0 -> ReadPrec [a0] -> ReadPrec [K a a0] #
Show a => Show1 (K a :: Type -> Type)	Since: sop-core-0.2.4.0
Instance details Defined in Data.SOP.BasicFunctors Methods liftShowsPrec :: (Int -> a0 -> ShowS) -> ([a0] -> ShowS) -> Int -> K a a0 -> ShowS # liftShowList :: (Int -> a0 -> ShowS) -> ([a0] -> ShowS) -> [K a a0] -> ShowS #
NFData a => NFData1 (K a :: Type -> Type)	Since: sop-core-0.2.5.0
Instance details Defined in Data.SOP.BasicFunctors Methods liftRnf :: (a0 -> ()) -> K a a0 -> () #
Eq a => Eq (K a b)
Instance details Defined in Data.SOP.BasicFunctors Methods (==) :: K a b -> K a b -> Bool # (/=) :: K a b -> K a b -> Bool #
Ord a => Ord (K a b)
Instance details Defined in Data.SOP.BasicFunctors Methods compare :: K a b -> K a b -> Ordering # (<) :: K a b -> K a b -> Bool # (<=) :: K a b -> K a b -> Bool # (>) :: K a b -> K a b -> Bool # (>=) :: K a b -> K a b -> Bool # max :: K a b -> K a b -> K a b # min :: K a b -> K a b -> K a b #
Read a => Read (K a b)
Instance details Defined in Data.SOP.BasicFunctors Methods readsPrec :: Int -> ReadS (K a b) # readList :: ReadS [K a b] # readPrec :: ReadPrec (K a b) # readListPrec :: ReadPrec [K a b] #
Show a => Show (K a b)
Instance details Defined in Data.SOP.BasicFunctors Methods showsPrec :: Int -> K a b -> ShowS # show :: K a b -> String # showList :: [K a b] -> ShowS #
Generic (K a b)
Instance details Defined in Data.SOP.BasicFunctors Associated Types type Rep (K a b) :: Type -> Type # Methods from :: K a b -> Rep (K a b) x # to :: Rep (K a b) x -> K a b #
Semigroup a => Semigroup (K a b)	Since: sop-core-0.4.0.0
Instance details Defined in Data.SOP.BasicFunctors Methods (<>) :: K a b -> K a b -> K a b # sconcat :: NonEmpty (K a b) -> K a b # stimes :: Integral b0 => b0 -> K a b -> K a b #
Monoid a => Monoid (K a b)	Since: sop-core-0.4.0.0
Instance details Defined in Data.SOP.BasicFunctors Methods mempty :: K a b # mappend :: K a b -> K a b -> K a b # mconcat :: [K a b] -> K a b #
NFData a => NFData (K a b)	Since: sop-core-0.2.5.0
Instance details Defined in Data.SOP.BasicFunctors Methods rnf :: K a b -> () #
type Rep (K a b)
Instance details Defined in Data.SOP.BasicFunctors type Rep (K a b) = D1 (MetaData "K" "Data.SOP.BasicFunctors" "sop-core-0.5.0.1-CJJL01S53WkJifrHVaTMB5" True) (C1 (MetaCons "K" PrefixI False) (S1 (MetaSel (Nothing :: Maybe Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 a)))
type Code (K a b)
Instance details Defined in Generics.SOP.Instances type Code (K a b) = (a ': ([] :: [Type])) ': ([] :: [[Type]])
type DatatypeInfoOf (K a b)
Instance details Defined in Generics.SOP.Instances type DatatypeInfoOf (K a b) = Newtype "Data.SOP.BasicFunctors" "K" (Constructor "K")

unK :: K a b -> a #

Extract the contents of a K value.