Snap.App.Model

Model running.

Documentation

model :: AppLiftModel c s => Model c s a -> Controller c s a

Run a model action from within a controller.

runDB :: s -> c -> Pool -> Model c s () -> IO ()

Run a model action at the top-level.

query :: (ToRow ps, FromRow r) => [String] -> ps -> Model c s [r]

Query with some parameters.

single :: (ToRow ps, FromRow (Only r)) => [String] -> ps -> Model c s (Maybe r)

Query a single field from a single result.

singleNoParams :: FromRow (Only r) => [String] -> Model c s (Maybe r)

Query a single field from a single result (no params).

queryNoParams :: FromRow r => [String] -> Model c s [r]

Query with no parameters.

withPoolConnection :: (MonadCatchIO m, MonadIO m) => Pool -> (Connection -> m a) -> m ()

Use the connection pool.

exec :: ToRow ps => [String] -> ps -> Model c s Int64

Execute some SQL returning the rows affected.

newtype Only a

A single-value "collection".

This is useful if you need to supply a single parameter to a SQL query, or extract a single column from a SQL result.

Parameter example:

query c "select x from scores where x > ?" (Only (42::Int))

Result example:

xs <- query_ c "select id from users"
forM_ xs $ \(Only id) -> {- ... -}

Constructors

Only

Fields

fromOnly :: a

Instances

Functor Only

Typeable1 Only

Eq a => Eq (Only a)

Ord a => Ord (Only a)

Read a => Read (Only a)

Show a => Show (Only a)

FromField a => FromRow (Only a)

ToField a => ToRow (Only a)

newPool

Arguments

:: MonadIO m

=> ConnectInfo

Connect info.

-> m Pool

Create a new connection pool.

data Pool