| Copyright |
(c) 2011 MailRank Inc.
(c) 2011-2012 Leon P Smith (c) 2012-2013 Janne Hellsten |
|---|---|
| License | BSD3 |
| Maintainer | Janne Hellsten <jjhellst@gmail.com> |
| Portability | portable |
| Safe Haskell | None |
| Language | Haskell2010 |
Database.SQLite.Simple.Types
Description
Top-level module for sqlite-simple.
Documentation
A placeholder for the SQL
NULL
value.
Constructors
| Null |
The 1-tuple type or single-value "collection".
This type is structurally equivalent to the
Identity
type, but its intent is more
about serving as the anonymous 1-tuple type missing from Haskell for attaching
typeclass instances.
Parameter usage example:
encodeSomething (Only (42::Int))
Result usage example:
xs <- decodeSomething
forM_ xs $ \(Only id) -> {- ... -}
Instances
| Functor Only | |
| Eq a => Eq ( Only a) | |
| Data a => Data ( Only a) | |
|
Defined in Data.Tuple.Only Methods gfoldl :: ( forall d b. Data d => c (d -> b) -> d -> c b) -> ( forall g. g -> c g) -> Only a -> c ( Only a) Source # gunfold :: ( forall b r. Data b => c (b -> r) -> c r) -> ( forall r. r -> c r) -> Constr -> c ( Only a) Source # toConstr :: Only a -> Constr Source # dataTypeOf :: Only a -> DataType Source # dataCast1 :: Typeable t => ( forall d. Data d => c (t d)) -> Maybe (c ( Only a)) Source # dataCast2 :: Typeable t => ( forall d e. ( Data d, Data e) => c (t d e)) -> Maybe (c ( Only a)) Source # gmapT :: ( forall b. Data b => b -> b) -> Only a -> Only a Source # gmapQl :: (r -> r' -> r) -> r -> ( forall d. Data d => d -> r') -> Only a -> r Source # gmapQr :: forall r r'. (r' -> r -> r) -> r -> ( forall d. Data d => d -> r') -> Only a -> r Source # gmapQ :: ( forall d. Data d => d -> u) -> Only a -> [u] Source # gmapQi :: Int -> ( forall d. Data d => d -> u) -> Only a -> u Source # gmapM :: Monad m => ( forall d. Data d => d -> m d) -> Only a -> m ( Only a) Source # gmapMp :: MonadPlus m => ( forall d. Data d => d -> m d) -> Only a -> m ( Only a) Source # gmapMo :: MonadPlus m => ( forall d. Data d => d -> m d) -> Only a -> m ( Only a) Source # |
|
| Ord a => Ord ( Only a) | |
| Read a => Read ( Only a) | |
| Show a => Show ( Only a) | |
| Generic ( Only a) | |
| NFData a => NFData ( Only a) | |
|
Defined in Data.Tuple.Only |
|
| ToField a => ToRow ( Only a) Source # | |
| FromField a => FromRow ( Only a) Source # | |
| type Rep ( Only a) | |
|
Defined in Data.Tuple.Only |
|
A query string. This type is intended to make it difficult to construct a SQL query by concatenating string fragments, as that is an extremely common way to accidentally introduce SQL injection vulnerabilities into an application.
This type is an instance of
IsString
, so the easiest way to
construct a query is to enable the
OverloadedStrings
language
extension and then simply write the query in double quotes.
{-# LANGUAGE OverloadedStrings #-}
import Database.SQLite.Simple
q :: Query
q = "select ?"
The underlying type is a
Text
, and literal Haskell strings that
contain Unicode characters will be correctly transformed to UTF-8.
A composite type to parse your custom data structures without having to define dummy newtype wrappers every time.
instance FromRow MyData where ...
instance FromRow MyData2 where ...
then I can do the following for free:
res <- query' c "..."
forM res $ \(MyData{..} :. MyData2{..}) -> do
....
Constructors
| h :. t infixr 3 |
Instances
| ( Eq h, Eq t) => Eq (h :. t) Source # | |
| ( Ord h, Ord t) => Ord (h :. t) Source # | |
|
Defined in Database.SQLite.Simple.Types |
|
| ( Read h, Read t) => Read (h :. t) Source # | |
| ( Show h, Show t) => Show (h :. t) Source # | |
| ( ToRow a, ToRow b) => ToRow (a :. b) Source # | |
| ( FromRow a, FromRow b) => FromRow (a :. b) Source # | |