| Safe Haskell | None |
|---|---|
| Language | Haskell2010 |
Database.Selda.Backend
Description
API for building Selda backends and adding support for more types in queries.
- class MonadIO m => MonadSelda m where
- data SeldaT m a
- type SeldaM = SeldaT IO
- data SeldaError
- data StmtID
- data BackendID
- = SQLite
- | PostgreSQL
- | Other Text
- type QueryRunner a = Text -> [Param] -> IO a
- data SeldaBackend = SeldaBackend {
- runStmt :: Text -> [Param] -> IO (Int, [[SqlValue]])
- runStmtWithPK :: Text -> [Param] -> IO Int
- prepareStmt :: StmtID -> [SqlTypeRep] -> Text -> IO Dynamic
- runPrepared :: Dynamic -> [Param] -> IO (Int, [[SqlValue]])
- ppConfig :: PPConfig
- closeConnection :: SeldaConnection -> IO ()
- backendId :: BackendID
- data SeldaConnection
- class Typeable a => SqlType a where
- data SqlValue where
- data SqlTypeRep
- data Param where
- data Lit a where
- LText :: !Text -> Lit Text
- LInt :: !Int -> Lit Int
- LDouble :: !Double -> Lit Double
- LBool :: !Bool -> Lit Bool
- LDateTime :: !Text -> Lit UTCTime
- LDate :: !Text -> Lit Day
- LTime :: !Text -> Lit TimeOfDay
- LJust :: SqlType a => !(Lit a) -> Lit (Maybe a)
- LBlob :: !ByteString -> Lit ByteString
- LNull :: SqlType a => Lit (Maybe a)
- LCustom :: Lit a -> Lit b
- data ColAttr
- data PPConfig = PPConfig {
- ppType :: SqlTypeRep -> Text
- ppPlaceholder :: Int -> Text
- ppColAttrs :: [ColAttr] -> Text
- ppAutoIncInsert :: Text
- defPPConfig :: PPConfig
- newConnection :: MonadIO m => SeldaBackend -> Text -> m SeldaConnection
- allStmts :: SeldaConnection -> IO [(StmtID, Dynamic)]
- seldaBackend :: MonadSelda m => m SeldaBackend
- runSeldaT :: (MonadIO m, MonadMask m) => SeldaT m a -> SeldaConnection -> m a
- seldaClose :: MonadIO m => SeldaConnection -> m ()
- sqlDateTimeFormat :: String
- sqlDateFormat :: String
- sqlTimeFormat :: String
Documentation
class MonadIO m => MonadSelda m where Source #
Some monad with Selda SQL capabilitites.
Minimal complete definition
seldaConnection, invalidateTable, beginTransaction, endTransaction
Methods
seldaConnection :: m SeldaConnection Source #
Get the connection in use by the computation.
invalidateTable :: Table a -> m () Source #
Invalidate the given table as soon as the current transaction finishes. Invalidate the table immediately if no transaction is ongoing.
beginTransaction :: m () Source #
Indicates the start of a new transaction.
Starts bookkeeping to invalidate all tables modified during
the transaction at the next call to endTransaction.
endTransaction :: Bool -> m () Source #
Indicates the end of the current transaction.
Invalidates all tables that were modified since the last call to
beginTransaction, unless the transaction was rolled back.
Instances
| MonadIO m => MonadSelda (SeldaT m) Source # | |
Monad transformer adding Selda SQL capabilities.
Instances
| MonadTrans SeldaT Source # | |
| Monad m => Monad (SeldaT m) Source # | |
| Functor m => Functor (SeldaT m) Source # | |
| Monad m => Applicative (SeldaT m) Source # | |
| MonadIO m => MonadIO (SeldaT m) Source # | |
| MonadThrow m => MonadThrow (SeldaT m) Source # | |
| MonadCatch m => MonadCatch (SeldaT m) Source # | |
| MonadMask m => MonadMask (SeldaT m) Source # | |
| MonadIO m => MonadSelda (SeldaT m) Source # | |
data SeldaError Source #
Thrown by any function in SeldaT if an error occurs.
Constructors
| DbError String | Unable to open or connect to database. |
| SqlError String | An error occurred while executing query. |
Instances
A prepared statement identifier. Guaranteed to be unique per application.
Uniquely identifies some particular backend.
When publishing a new backend, consider submitting a pull request with a
constructor for your backend instead of using the Other constructor.
Constructors
| SQLite | |
| PostgreSQL | |
| Other Text |
type QueryRunner a = Text -> [Param] -> IO a Source #
A function which executes a query and gives back a list of extensible tuples; one tuple per result row, and one tuple element per column.
data SeldaBackend Source #
A collection of functions making up a Selda backend.
Constructors
| SeldaBackend | |
Fields
| |
data SeldaConnection Source #
class Typeable a => SqlType a where Source #
Any datatype representable in (Selda's subset of) SQL.
Minimal complete definition
Some value that is representable in SQL.
A parameter to a prepared SQL statement.
An SQL literal.
Constructors
| LText :: !Text -> Lit Text | |
| LInt :: !Int -> Lit Int | |
| LDouble :: !Double -> Lit Double | |
| LBool :: !Bool -> Lit Bool | |
| LDateTime :: !Text -> Lit UTCTime | |
| LDate :: !Text -> Lit Day | |
| LTime :: !Text -> Lit TimeOfDay | |
| LJust :: SqlType a => !(Lit a) -> Lit (Maybe a) | |
| LBlob :: !ByteString -> Lit ByteString | |
| LNull :: SqlType a => Lit (Maybe a) | |
| LCustom :: Lit a -> Lit b |
Column attributes such as nullability, auto increment, etc. When adding elements, make sure that they are added in the order required by SQL syntax, as this list is only sorted before being pretty-printed.
Constructors
| Primary | |
| AutoIncrement | |
| Required | |
| Optional | |
| Unique |
Backend-specific configuration for the SQL pretty-printer.
Constructors
| PPConfig | |
Fields
| |
defPPConfig :: PPConfig Source #
Default settings for pretty-printing. Geared towards SQLite.
newConnection :: MonadIO m => SeldaBackend -> Text -> m SeldaConnection Source #
Create a new Selda connection for the given backend and database identifier string.
allStmts :: SeldaConnection -> IO [(StmtID, Dynamic)] Source #
Get all statements and their corresponding identifiers for the current connection.
seldaBackend :: MonadSelda m => m SeldaBackend Source #
Get the backend in use by the computation.
runSeldaT :: (MonadIO m, MonadMask m) => SeldaT m a -> SeldaConnection -> m a Source #
Run a Selda transformer. Backends should use this to implement their
withX functions.
seldaClose :: MonadIO m => SeldaConnection -> m () Source #
Close a reusable Selda connection.
Closing a connection while in use is undefined.
Passing a closed connection to runSeldaT results in a SeldaError
being thrown. Closing a connection more than once is a no-op.
sqlDateTimeFormat :: String Source #
Format string used to represent date and time when talking to the database backend.
sqlDateFormat :: String Source #
Format string used to represent date when talking to the database backend.
sqlTimeFormat :: String Source #
Format string used to represent time of day when talking to the database backend.