Safe Haskell	None
Language	Haskell2010

Hasql.DynamicStatements.Snippet

Synopsis

data Snippet
param :: DefaultParamEncoder param => param -> Snippet
encoderAndParam :: NullableOrNot Value param -> param -> Snippet
sql :: ByteString -> Snippet

Documentation

data Snippet Source #

Composable SQL snippet with parameters injected. Abstracts over placeholders and matching of encoders.

It has an instance of IsString , so having the OverloadedStrings extension enabled you can construct it directly from string literals.

Here's an example:

selectSubstring :: Text -> Maybe Int32 -> Maybe Int32 -> Snippet 
selectSubstring string from to =
 "select substring(" <> param  string <>
 foldMap  (\ x -> " from " <> param  x) from <>
 foldMap  (\ x -> " for " <> param  x) to <>
 ")"

Having a decoder you can lift it into Statement using dynamicallyParameterized or directly execute it in Session using dynamicallyParameterizedStatement .

Instances

IsString Snippet Source #

Instance details

Defined in Hasql.DynamicStatements.Snippet.Defs

Methods

fromString :: String -> Snippet #

Semigroup Snippet Source #

Instance details

Defined in Hasql.DynamicStatements.Snippet.Defs

Methods

(<>) :: Snippet -> Snippet -> Snippet #

sconcat :: NonEmpty Snippet -> Snippet #

stimes :: Integral b => b -> Snippet -> Snippet #

Monoid Snippet Source #

Instance details

Defined in Hasql.DynamicStatements.Snippet.Defs

Methods

mempty :: Snippet #

mappend :: Snippet -> Snippet -> Snippet #

mconcat :: [Snippet] -> Snippet #

param :: DefaultParamEncoder param => param -> Snippet Source #

Parameter encoded using an implicitly derived encoder from the type.

encoderAndParam :: NullableOrNot Value param -> param -> Snippet Source #

Parameter with an explicitly defined encoder.

sql :: ByteString -> Snippet Source #

SQL chunk in ASCII.