selda-0.5.1.0: Multi-backend, high-level EDSL for interacting with SQL databases.

Safe HaskellNone
LanguageHaskell2010

Database.Selda.Backend.Internal

Description

Internal backend API. Using anything exported from this module may or may not invalidate any safety guarantees made by Selda; use at your own peril.

Synopsis

Documentation

newtype StmtID Source #

A prepared statement identifier. Guaranteed to be unique per application.

Constructors

StmtID Int 
Instances
Eq StmtID Source # 
Instance details

Defined in Database.Selda.Backend.Internal

Methods

(==) :: StmtID -> StmtID -> Bool #

(/=) :: StmtID -> StmtID -> Bool #

Ord StmtID Source # 
Instance details

Defined in Database.Selda.Backend.Internal

Show StmtID Source # 
Instance details

Defined in Database.Selda.Backend.Internal

data BackendID Source #

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 b Source #

A collection of functions making up a Selda backend.

Constructors

SeldaBackend 

Fields

data SeldaConnection b Source #

Constructors

SeldaConnection 

Fields

data SeldaStmt Source #

A prepared statement.

Constructors

SeldaStmt 

Fields

  • stmtHandle :: !Dynamic

    Backend-specific handle to the prepared statement.

  • stmtText :: !Text

    The SQL code for the statement.

  • stmtParams :: ![Either Int Param]

    All parameters to be passed to the prepared statement. Parameters that are unique to each invocation are specified as indices starting at 0. Backends implementing runPrepared should probably ignore this field.

class MonadIO m => MonadSelda m where Source #

Some monad with Selda SQL capabilitites.

Minimal complete definition

withConnection

Associated Types

type Backend m Source #

Type of database backend used by m.

Methods

withConnection :: (SeldaConnection (Backend m) -> m a) -> m a Source #

Pass a Selda connection to the given computation and execute it. After the computation finishes, withConnection is free to do anything it likes to the connection, including closing it or giving it to another Selda computation. Thus, the computation must take care never to return or otherwise access the connection after returning.

transact :: m a -> m a Source #

Perform the given computation as a transaction. Implementations must ensure that subsequent calls to withConnection within the same transaction always passes the same connection to its argument.

Instances
(MonadIO m, MonadMask m) => MonadSelda (SeldaT b m) Source # 
Instance details

Defined in Database.Selda.Backend.Internal

Associated Types

type Backend (SeldaT b m) :: Type Source #

Methods

withConnection :: (SeldaConnection (Backend (SeldaT b m)) -> SeldaT b m a) -> SeldaT b m a Source #

transact :: SeldaT b m a -> SeldaT b m a Source #

newtype SeldaT b m a Source #

Monad transformer adding Selda SQL capabilities.

Constructors

S 

Fields

Instances
MonadTrans (SeldaT b) Source # 
Instance details

Defined in Database.Selda.Backend.Internal

Methods

lift :: Monad m => m a -> SeldaT b m a #

Monad m => Monad (SeldaT b m) Source # 
Instance details

Defined in Database.Selda.Backend.Internal

Methods

(>>=) :: SeldaT b m a -> (a -> SeldaT b m b0) -> SeldaT b m b0 #

(>>) :: SeldaT b m a -> SeldaT b m b0 -> SeldaT b m b0 #

return :: a -> SeldaT b m a #

fail :: String -> SeldaT b m a #

Functor m => Functor (SeldaT b m) Source # 
Instance details

Defined in Database.Selda.Backend.Internal

Methods

fmap :: (a -> b0) -> SeldaT b m a -> SeldaT b m b0 #

(<$) :: a -> SeldaT b m b0 -> SeldaT b m a #

MonadFail m => MonadFail (SeldaT b m) Source # 
Instance details

Defined in Database.Selda.Backend.Internal

Methods

fail :: String -> SeldaT b m a #

Monad m => Applicative (SeldaT b m) Source # 
Instance details

Defined in Database.Selda.Backend.Internal

Methods

pure :: a -> SeldaT b m a #

(<*>) :: SeldaT b m (a -> b0) -> SeldaT b m a -> SeldaT b m b0 #

liftA2 :: (a -> b0 -> c) -> SeldaT b m a -> SeldaT b m b0 -> SeldaT b m c #

(*>) :: SeldaT b m a -> SeldaT b m b0 -> SeldaT b m b0 #

(<*) :: SeldaT b m a -> SeldaT b m b0 -> SeldaT b m a #

MonadIO m => MonadIO (SeldaT b m) Source # 
Instance details

Defined in Database.Selda.Backend.Internal

Methods

liftIO :: IO a -> SeldaT b m a #

MonadThrow m => MonadThrow (SeldaT b m) Source # 
Instance details

Defined in Database.Selda.Backend.Internal

Methods

throwM :: Exception e => e -> SeldaT b m a #

MonadCatch m => MonadCatch (SeldaT b m) Source # 
Instance details

Defined in Database.Selda.Backend.Internal

Methods

catch :: Exception e => SeldaT b m a -> (e -> SeldaT b m a) -> SeldaT b m a #

MonadMask m => MonadMask (SeldaT b m) Source # 
Instance details

Defined in Database.Selda.Backend.Internal

Methods

mask :: ((forall a. SeldaT b m a -> SeldaT b m a) -> SeldaT b m b0) -> SeldaT b m b0 #

uninterruptibleMask :: ((forall a. SeldaT b m a -> SeldaT b m a) -> SeldaT b m b0) -> SeldaT b m b0 #

generalBracket :: SeldaT b m a -> (a -> ExitCase b0 -> SeldaT b m c) -> (a -> SeldaT b m b0) -> SeldaT b m (b0, c) #

(MonadIO m, MonadMask m) => MonadSelda (SeldaT b m) Source # 
Instance details

Defined in Database.Selda.Backend.Internal

Associated Types

type Backend (SeldaT b m) :: Type Source #

Methods

withConnection :: (SeldaConnection (Backend (SeldaT b m)) -> SeldaT b m a) -> SeldaT b m a Source #

transact :: SeldaT b m a -> SeldaT b m a Source #

type Backend (SeldaT b m) Source # 
Instance details

Defined in Database.Selda.Backend.Internal

type Backend (SeldaT b m) = b

type SeldaM b = SeldaT b IO Source #

The simplest form of Selda computation; SeldaT specialized to IO.

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.

UnsafeError String

An error occurred due to improper use of an unsafe function.

data Param where Source #

A parameter to a prepared SQL statement.

Constructors

Param :: !(Lit a) -> Param 
Instances
Eq Param Source # 
Instance details

Defined in Database.Selda.SQL

Methods

(==) :: Param -> Param -> Bool #

(/=) :: Param -> Param -> Bool #

Ord Param Source # 
Instance details

Defined in Database.Selda.SQL

Methods

compare :: Param -> Param -> Ordering #

(<) :: Param -> Param -> Bool #

(<=) :: Param -> Param -> Bool #

(>) :: Param -> Param -> Bool #

(>=) :: Param -> Param -> Bool #

max :: Param -> Param -> Param #

min :: Param -> Param -> Param #

Show Param Source # 
Instance details

Defined in Database.Selda.SQL

Methods

showsPrec :: Int -> Param -> ShowS #

show :: Param -> String #

showList :: [Param] -> ShowS #

data Lit a where Source #

An SQL literal.

Constructors

LText :: !Text -> Lit Text 
LInt :: !Int -> Lit Int 
LDouble :: !Double -> Lit Double 
LBool :: !Bool -> Lit Bool 
LDateTime :: !UTCTime -> Lit UTCTime 
LDate :: !Day -> Lit Day 
LTime :: !TimeOfDay -> Lit TimeOfDay 
LJust :: SqlType a => !(Lit a) -> Lit (Maybe a) 
LBlob :: !ByteString -> Lit ByteString 
LNull :: SqlType a => Lit (Maybe a) 
LCustom :: SqlTypeRep -> Lit a -> Lit b 
LUUID :: !UUID -> Lit UUID 
Instances
Eq (Lit a) Source # 
Instance details

Defined in Database.Selda.SqlType

Methods

(==) :: Lit a -> Lit a -> Bool #

(/=) :: Lit a -> Lit a -> Bool #

Ord (Lit a) Source # 
Instance details

Defined in Database.Selda.SqlType

Methods

compare :: Lit a -> Lit a -> Ordering #

(<) :: Lit a -> Lit a -> Bool #

(<=) :: Lit a -> Lit a -> Bool #

(>) :: Lit a -> Lit a -> Bool #

(>=) :: Lit a -> Lit a -> Bool #

max :: Lit a -> Lit a -> Lit a #

min :: Lit a -> Lit a -> Lit a #

Show (Lit a) Source # 
Instance details

Defined in Database.Selda.SqlType

Methods

showsPrec :: Int -> Lit a -> ShowS #

show :: Lit a -> String #

showList :: [Lit a] -> ShowS #

data ColAttr Source #

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.

Instances
Eq ColAttr Source # 
Instance details

Defined in Database.Selda.Table.Type

Methods

(==) :: ColAttr -> ColAttr -> Bool #

(/=) :: ColAttr -> ColAttr -> Bool #

Ord ColAttr Source # 
Instance details

Defined in Database.Selda.Table.Type

Show ColAttr Source # 
Instance details

Defined in Database.Selda.Table.Type

class Typeable a => SqlType a where Source #

Any datatype representable in (Selda's subset of) SQL.

Minimal complete definition

Nothing

Methods

mkLit :: a -> Lit a Source #

Create a literal of this type.

mkLit :: (Typeable a, SqlEnum a) => a -> Lit a Source #

Create a literal of this type.

sqlType :: Proxy a -> SqlTypeRep Source #

The SQL representation for this type.

fromSql :: SqlValue -> a Source #

Convert an SqlValue into this type.

fromSql :: (Typeable a, SqlEnum a) => SqlValue -> a Source #

Convert an SqlValue into this type.

defaultValue :: Lit a Source #

Default value when using def at this type.

defaultValue :: (Typeable a, SqlEnum a) => Lit a Source #

Default value when using def at this type.

Instances
SqlType Bool Source # 
Instance details

Defined in Database.Selda.SqlType

SqlType Double Source # 
Instance details

Defined in Database.Selda.SqlType

SqlType Int Source # 
Instance details

Defined in Database.Selda.SqlType

SqlType Ordering Source # 
Instance details

Defined in Database.Selda.SqlType

SqlType ByteString Source # 
Instance details

Defined in Database.Selda.SqlType

SqlType ByteString Source # 
Instance details

Defined in Database.Selda.SqlType

SqlType Text Source # 
Instance details

Defined in Database.Selda.SqlType

SqlType TimeOfDay Source # 
Instance details

Defined in Database.Selda.SqlType

SqlType UTCTime Source # 
Instance details

Defined in Database.Selda.SqlType

SqlType Day Source # 
Instance details

Defined in Database.Selda.SqlType

SqlType UUID Source #

defaultValue for UUIDs is the all-zero RFC4122 nil UUID.

Instance details

Defined in Database.Selda.SqlType

SqlType RowID Source # 
Instance details

Defined in Database.Selda.SqlType

SqlType a => SqlType (Maybe a) Source # 
Instance details

Defined in Database.Selda.SqlType

Typeable a => SqlType (ID a) Source # 
Instance details

Defined in Database.Selda.SqlType

((TypeError (((Text "'Only " :<>: ShowType a) :<>: Text "' is not a proper SQL type.") :$$: Text "Use 'the' to access the value of the column.") :: Constraint), Typeable a) => SqlType (Only a) Source # 
Instance details

Defined in Database.Selda

data SqlValue where Source #

Some value that is representable in SQL.

Instances
Show SqlValue Source # 
Instance details

Defined in Database.Selda.SqlType

data PPConfig Source #

Backend-specific configuration for the SQL pretty-printer.

Constructors

PPConfig 

Fields

  • ppType :: SqlTypeRep -> Text

    The SQL type name of the given type.

    This function should be used everywhere a type is needed to be printed but in primary keys position. This is due to the fact that some backends might have a special representation of primary keys (using sequences are such). If you have such a need, please use the ppTypePK record instead.

  • ppTypeHook :: SqlTypeRep -> [ColAttr] -> (SqlTypeRep -> Text) -> Text

    Hook that allows you to modify ppType output.

  • ppTypePK :: SqlTypeRep -> Text

    The SQL type name of the given type for primary keys uses.

  • ppPlaceholder :: Int -> Text

    Parameter placeholder for the nth parameter.

  • ppColAttrs :: [ColAttr] -> Text

    List of column attributes.

  • ppColAttrsHook :: SqlTypeRep -> [ColAttr] -> ([ColAttr] -> Text) -> Text

    Hook that allows you to modify ppColAttrs output.

  • ppAutoIncInsert :: Text

    The value used for the next value for an auto-incrementing column. For instance, DEFAULT for PostgreSQL, and NULL for SQLite.

  • ppMaxInsertParams :: Maybe Int

    Insert queries may have at most this many parameters; if an insertion has more parameters than this, it will be chunked.

    Note that only insertions of multiple rows are chunked. If your table has more than this many columns, you should really rethink your database design.

  • ppIndexMethodHook :: IndexMethod -> Text

    CREATE INDEX suffix to indicate that the index should use the given index method.

defPPConfig :: PPConfig Source #

Default settings for pretty-printing. Geared towards SQLite.

The default definition of ppTypePK is 'defType, so that you don’t have to do anything special if you don’t use special types for primary keys.

data TableInfo Source #

Comprehensive information about a table.

Constructors

TableInfo 

Fields

Instances
Eq TableInfo Source # 
Instance details

Defined in Database.Selda.Backend.Internal

Show TableInfo Source # 
Instance details

Defined in Database.Selda.Backend.Internal

data ColumnInfo Source #

Comprehensive information about a column.

Constructors

ColumnInfo 

Fields

tableInfo :: Table a -> TableInfo Source #

Get the column information for each column in the given table.

fromColInfo :: ColInfo -> ColumnInfo Source #

Convert a ColInfo into a ColumnInfo.

sqlDateTimeFormat :: String Source #

Format string used to represent date and time when representing timestamps as text. If at all possible, use SqlUTCTime instead.

sqlDateFormat :: String Source #

Format string used to represent date when representing dates as text. If at all possible, use SqlDate instead.

sqlTimeFormat :: String Source #

Format string used to represent time of day when representing time as text. If at all possible, use SqlTime instead.

freshStmtId :: MonadIO m => m StmtID Source #

Generate a fresh statement identifier, guaranteed to be unique per process.

newConnection :: MonadIO m => SeldaBackend b -> Text -> m (SeldaConnection b) Source #

Create a new Selda connection for the given backend and database identifier string.

allStmts :: SeldaConnection b -> IO [(StmtID, Dynamic)] Source #

Get all statements and their corresponding identifiers for the current connection.

runSeldaT :: (MonadIO m, MonadMask m) => SeldaT b m a -> SeldaConnection b -> m a Source #

Run a Selda transformer. Backends should use this to implement their withX functions.

withBackend :: MonadSelda m => (SeldaBackend (Backend m) -> m a) -> m a Source #

Get the backend in use by the computation.