Database.Selda.Backend.Internal

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.

Documentation

newtype StmtID

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

Constructors

StmtID Int

Instances

Show StmtID

Defined in Database.Selda.Backend.Internal

Methods

showsPrec :: Int -> StmtID -> ShowS

show :: StmtID -> String

showList :: [StmtID] -> ShowS

Eq StmtID

Defined in Database.Selda.Backend.Internal

Methods

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

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

Ord StmtID

Defined in Database.Selda.Backend.Internal

Methods

compare :: StmtID -> StmtID -> Ordering

(<) :: StmtID -> StmtID -> Bool

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

(>) :: StmtID -> StmtID -> Bool

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

max :: StmtID -> StmtID -> StmtID

min :: StmtID -> StmtID -> StmtID

data BackendID

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

Instances

Show BackendID

Defined in Database.Selda.Backend.Internal

Methods

showsPrec :: Int -> BackendID -> ShowS

show :: BackendID -> String

showList :: [BackendID] -> ShowS

Eq BackendID

Defined in Database.Selda.Backend.Internal

Methods

(==) :: BackendID -> BackendID -> Bool

(/=) :: BackendID -> BackendID -> Bool

Ord BackendID

Defined in Database.Selda.Backend.Internal

Methods

compare :: BackendID -> BackendID -> Ordering

(<) :: BackendID -> BackendID -> Bool

(<=) :: BackendID -> BackendID -> Bool

(>) :: BackendID -> BackendID -> Bool

(>=) :: BackendID -> BackendID -> Bool

max :: BackendID -> BackendID -> BackendID

min :: BackendID -> BackendID -> BackendID

type QueryRunner a = Text -> [Param] -> IO a

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

A collection of functions making up a Selda backend.

Constructors

SeldaBackend

Fields

• runStmt :: Text -> [Param] -> IO (Int, [[SqlValue]])

  Execute an SQL statement.

• runStmtWithPK :: Text -> [Param] -> IO Int64

  Execute an SQL statement and return the last inserted primary key, where the primary key is auto-incrementing. Backends must take special care to make this thread-safe.

• prepareStmt :: StmtID -> [SqlTypeRep] -> Text -> IO Dynamic

  Prepare a statement using the given statement identifier.

• runPrepared :: Dynamic -> [Param] -> IO (Int, [[SqlValue]])

  Execute a prepared statement.

• getTableInfo :: TableName -> IO TableInfo

  Get a list of all columns in the given table, with the type and any modifiers for each column. Return an empty list if the given table does not exist.

• ppConfig :: PPConfig

  SQL pretty-printer configuration.

• closeConnection :: SeldaConnection b -> IO ()

  Close the currently open connection.

• backendId :: BackendID

  Unique identifier for this backend.

• disableForeignKeys :: Bool -> IO ()

  Turn on or off foreign key checking, and initiate/commit a transaction.

  When implementing this function, it is safe to assume that disableForeignKeys True will always be called exactly once before each disableForeignKeys False.

data SeldaConnection b

Constructors

SeldaConnection

Fields

• connBackend :: !(SeldaBackend b)

  The backend used by the current connection.

• connDbId :: Text

  A string uniquely identifying the database used by this connection. This could be, for instance, a PostgreSQL connection string or the absolute path to an SQLite file.

• connStmts :: !(IORef (IntMap SeldaStmt))

  All statements prepared for this connection.

• connClosed :: !(IORef Bool)

  Is the connection closed?

• connLock :: !(MVar ())

  Lock to prevent this connection from being used concurrently by multiple invocations of runSeldaT.

data SeldaStmt

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

Some monad with Selda SQL capabilitites.

Minimal complete definition

withConnection

Associated Types

type Backend m

Type of database backend used by m.

Methods

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

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

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)

Defined in Database.Selda.Backend.Internal

Associated Types

type Backend (SeldaT b m)

Methods

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

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

newtype SeldaT b m a

Monad transformer adding Selda SQL capabilities.

Constructors

S

Fields

• unS :: ReaderT (SeldaConnection b) m a

Instances

MonadTrans (SeldaT b)

Defined in Database.Selda.Backend.Internal

Methods

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

MonadFail m => MonadFail (SeldaT b m)

Defined in Database.Selda.Backend.Internal

Methods

fail :: String -> SeldaT b m a

MonadIO m => MonadIO (SeldaT b m)

Defined in Database.Selda.Backend.Internal

Methods

liftIO :: IO a -> SeldaT b m a

Applicative m => Applicative (SeldaT b m)

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

Functor m => Functor (SeldaT b m)

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

Monad m => Monad (SeldaT b m)

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

MonadCatch m => MonadCatch (SeldaT b m)

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)

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)

MonadThrow m => MonadThrow (SeldaT b m)

Defined in Database.Selda.Backend.Internal

Methods

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

(MonadIO m, MonadMask m) => MonadSelda (SeldaT b m)

Defined in Database.Selda.Backend.Internal

Associated Types

type Backend (SeldaT b m)

Methods

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

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

type Backend (SeldaT b m)

Defined in Database.Selda.Backend.Internal

type Backend (SeldaT b m) = b

type SeldaM b = SeldaT b IO

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

data SeldaError

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.

Instances

Exception SeldaError

Defined in Database.Selda.Backend.Internal

Methods

toException :: SeldaError -> SomeException

fromException :: SomeException -> Maybe SeldaError

displayException :: SeldaError -> String

Show SeldaError

Defined in Database.Selda.Backend.Internal

Methods

showsPrec :: Int -> SeldaError -> ShowS

show :: SeldaError -> String

showList :: [SeldaError] -> ShowS

Eq SeldaError

Defined in Database.Selda.Backend.Internal

Methods

(==) :: SeldaError -> SeldaError -> Bool

(/=) :: SeldaError -> SeldaError -> Bool

data Param where

A parameter to a prepared SQL statement.

Constructors

Param :: !(Lit a) -> Param

Instances

Show Param

Defined in Database.Selda.SQL

Methods

showsPrec :: Int -> Param -> ShowS

show :: Param -> String

showList :: [Param] -> ShowS

Eq Param

Defined in Database.Selda.SQL

Methods

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

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

Ord Param

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

data Lit a where

An SQL literal.

Constructors

LText :: !Text -> Lit Text

LInt32 :: !Int32 -> Lit Int32

LInt64 :: !Int64 -> Lit Int64

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

Show (Lit a)

Defined in Database.Selda.SqlType

Methods

showsPrec :: Int -> Lit a -> ShowS

show :: Lit a -> String

showList :: [Lit a] -> ShowS

Eq (Lit a)

Defined in Database.Selda.SqlType

Methods

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

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

Ord (Lit a)

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

data ColAttr

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

AutoPrimary AutoIncType

Required

Optional

Unique

Indexed (Maybe IndexMethod)

Instances

Show ColAttr

Defined in Database.Selda.Table.Type

Methods

showsPrec :: Int -> ColAttr -> ShowS

show :: ColAttr -> String

showList :: [ColAttr] -> ShowS

Eq ColAttr

Defined in Database.Selda.Table.Type

Methods

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

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

Ord ColAttr

Defined in Database.Selda.Table.Type

Methods

compare :: ColAttr -> ColAttr -> Ordering

(<) :: ColAttr -> ColAttr -> Bool

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

(>) :: ColAttr -> ColAttr -> Bool

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

max :: ColAttr -> ColAttr -> ColAttr

min :: ColAttr -> ColAttr -> ColAttr

data AutoIncType

Strongly or weakly auto-incrementing primary key?

Constructors

Weak

Strong

Instances

Show AutoIncType

Defined in Database.Selda.Table.Type

Methods

showsPrec :: Int -> AutoIncType -> ShowS

show :: AutoIncType -> String

showList :: [AutoIncType] -> ShowS

Eq AutoIncType

Defined in Database.Selda.Table.Type

Methods

(==) :: AutoIncType -> AutoIncType -> Bool

(/=) :: AutoIncType -> AutoIncType -> Bool

Ord AutoIncType

Defined in Database.Selda.Table.Type

Methods

compare :: AutoIncType -> AutoIncType -> Ordering

(<) :: AutoIncType -> AutoIncType -> Bool

(<=) :: AutoIncType -> AutoIncType -> Bool

(>) :: AutoIncType -> AutoIncType -> Bool

(>=) :: AutoIncType -> AutoIncType -> Bool

max :: AutoIncType -> AutoIncType -> AutoIncType

min :: AutoIncType -> AutoIncType -> AutoIncType

class Typeable a => SqlType a where

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

Minimal complete definition

Nothing

Methods

mkLit :: a -> Lit a

Create a literal of this type.

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

sqlType :: Proxy a -> SqlTypeRep

The SQL representation for this type.

fromSql :: SqlValue -> a

Convert an SqlValue into this type.

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

defaultValue :: Lit a

Default value when using def at this type.

default defaultValue :: (Typeable a, SqlEnum a) => Lit a

Instances

SqlType Int32

Defined in Database.Selda.SqlType

Methods

mkLit :: Int32 -> Lit Int32

sqlType :: Proxy Int32 -> SqlTypeRep

fromSql :: SqlValue -> Int32

defaultValue :: Lit Int32

SqlType Int64

Defined in Database.Selda.SqlType

Methods

mkLit :: Int64 -> Lit Int64

sqlType :: Proxy Int64 -> SqlTypeRep

fromSql :: SqlValue -> Int64

defaultValue :: Lit Int64

SqlType ByteString

Defined in Database.Selda.SqlType

Methods

mkLit :: ByteString -> Lit ByteString

sqlType :: Proxy ByteString -> SqlTypeRep

fromSql :: SqlValue -> ByteString

defaultValue :: Lit ByteString

SqlType ByteString

Defined in Database.Selda.SqlType

Methods

mkLit :: ByteString -> Lit ByteString

sqlType :: Proxy ByteString -> SqlTypeRep

fromSql :: SqlValue -> ByteString

defaultValue :: Lit ByteString

SqlType Ordering

Defined in Database.Selda.SqlType

Methods

mkLit :: Ordering -> Lit Ordering

sqlType :: Proxy Ordering -> SqlTypeRep

fromSql :: SqlValue -> Ordering

defaultValue :: Lit Ordering

SqlType RowID

Defined in Database.Selda.SqlType

Methods

mkLit :: RowID -> Lit RowID

sqlType :: Proxy RowID -> SqlTypeRep

fromSql :: SqlValue -> RowID

defaultValue :: Lit RowID

SqlType Text

Defined in Database.Selda.SqlType

Methods

mkLit :: Text -> Lit Text

sqlType :: Proxy Text -> SqlTypeRep

fromSql :: SqlValue -> Text

defaultValue :: Lit Text

SqlType Text

Defined in Database.Selda.SqlType

Methods

mkLit :: Text -> Lit Text

sqlType :: Proxy Text -> SqlTypeRep

fromSql :: SqlValue -> Text

defaultValue :: Lit Text

SqlType Day

Defined in Database.Selda.SqlType

Methods

mkLit :: Day -> Lit Day

sqlType :: Proxy Day -> SqlTypeRep

fromSql :: SqlValue -> Day

defaultValue :: Lit Day

SqlType UTCTime

Defined in Database.Selda.SqlType

Methods

mkLit :: UTCTime -> Lit UTCTime

sqlType :: Proxy UTCTime -> SqlTypeRep

fromSql :: SqlValue -> UTCTime

defaultValue :: Lit UTCTime

SqlType TimeOfDay

Defined in Database.Selda.SqlType

Methods

mkLit :: TimeOfDay -> Lit TimeOfDay

sqlType :: Proxy TimeOfDay -> SqlTypeRep

fromSql :: SqlValue -> TimeOfDay

defaultValue :: Lit TimeOfDay

SqlType UUID

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

Defined in Database.Selda.SqlType

Methods

mkLit :: UUID -> Lit UUID

sqlType :: Proxy UUID -> SqlTypeRep

fromSql :: SqlValue -> UUID

defaultValue :: Lit UUID

SqlType Bool

Defined in Database.Selda.SqlType

Methods

mkLit :: Bool -> Lit Bool

sqlType :: Proxy Bool -> SqlTypeRep

fromSql :: SqlValue -> Bool

defaultValue :: Lit Bool

SqlType Double

Defined in Database.Selda.SqlType

Methods

mkLit :: Double -> Lit Double

sqlType :: Proxy Double -> SqlTypeRep

fromSql :: SqlValue -> Double

defaultValue :: Lit Double

SqlType Int

Defined in Database.Selda.SqlType

Methods

mkLit :: Int -> Lit Int

sqlType :: Proxy Int -> SqlTypeRep

fromSql :: SqlValue -> Int

defaultValue :: Lit Int

(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)

Defined in Database.Selda

Methods

mkLit :: Only a -> Lit (Only a)

sqlType :: Proxy (Only a) -> SqlTypeRep

fromSql :: SqlValue -> Only a

defaultValue :: Lit (Only a)

Typeable a => SqlType (ID a)

Defined in Database.Selda.SqlType

Methods

mkLit :: ID a -> Lit (ID a)

sqlType :: Proxy (ID a) -> SqlTypeRep

fromSql :: SqlValue -> ID a

defaultValue :: Lit (ID a)

Typeable a => SqlType (UUID' a)

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

Defined in Database.Selda.SqlType

Methods

mkLit :: UUID' a -> Lit (UUID' a)

sqlType :: Proxy (UUID' a) -> SqlTypeRep

fromSql :: SqlValue -> UUID' a

defaultValue :: Lit (UUID' a)

SqlType a => SqlType (Maybe a)

Defined in Database.Selda.SqlType

Methods

mkLit :: Maybe a -> Lit (Maybe a)

sqlType :: Proxy (Maybe a) -> SqlTypeRep

fromSql :: SqlValue -> Maybe a

defaultValue :: Lit (Maybe a)

data SqlValue where

Some value that is representable in SQL.

Constructors

SqlInt32 :: !Int32 -> SqlValue

SqlInt64 :: !Int64 -> SqlValue

SqlFloat :: !Double -> SqlValue

SqlString :: !Text -> SqlValue

SqlBool :: !Bool -> SqlValue

SqlBlob :: !ByteString -> SqlValue

SqlUTCTime :: !UTCTime -> SqlValue

SqlTime :: !TimeOfDay -> SqlValue

SqlDate :: !Day -> SqlValue

SqlNull :: SqlValue

Instances

Show SqlValue

Defined in Database.Selda.SqlType

Methods

showsPrec :: Int -> SqlValue -> ShowS

show :: SqlValue -> String

showList :: [SqlValue] -> ShowS

data SqlTypeRep

Representation of an SQL type.

Constructors

TText

TRowID

TInt64

TInt32

TFloat

TBool

TDateTime

TDate

TTime

TBlob

TUUID

TJSON

Instances

Show SqlTypeRep

Defined in Database.Selda.SqlType

Methods

showsPrec :: Int -> SqlTypeRep -> ShowS

show :: SqlTypeRep -> String

showList :: [SqlTypeRep] -> ShowS

Eq SqlTypeRep

Defined in Database.Selda.SqlType

Methods

(==) :: SqlTypeRep -> SqlTypeRep -> Bool

(/=) :: SqlTypeRep -> SqlTypeRep -> Bool

Ord SqlTypeRep

Defined in Database.Selda.SqlType

Methods

compare :: SqlTypeRep -> SqlTypeRep -> Ordering

(<) :: SqlTypeRep -> SqlTypeRep -> Bool

(<=) :: SqlTypeRep -> SqlTypeRep -> Bool

(>) :: SqlTypeRep -> SqlTypeRep -> Bool

(>=) :: SqlTypeRep -> SqlTypeRep -> Bool

max :: SqlTypeRep -> SqlTypeRep -> SqlTypeRep

min :: SqlTypeRep -> SqlTypeRep -> SqlTypeRep

data PPConfig

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

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

Comprehensive information about a table.

Constructors

TableInfo

Fields

• tableInfoName :: TableName

  Name of the table.

• tableColumnInfos :: [ColumnInfo]

  Ordered information about each table column.

• tableUniqueGroups :: [[ColName]]

  Unordered list of all (non-PK) uniqueness constraints on this table.

• tablePrimaryKey :: [ColName]

  Unordered list of all primary key constraints on this table.

Instances

Show TableInfo

Defined in Database.Selda.Backend.Internal

Methods

showsPrec :: Int -> TableInfo -> ShowS

show :: TableInfo -> String

showList :: [TableInfo] -> ShowS

Eq TableInfo

Defined in Database.Selda.Backend.Internal

Methods

(==) :: TableInfo -> TableInfo -> Bool

(/=) :: TableInfo -> TableInfo -> Bool

data ColumnInfo

Comprehensive information about a column.

Constructors

ColumnInfo

Fields

• colName :: ColName

  Name of the column.

• colType :: Either Text SqlTypeRep

  Selda type of the column, or the type name given by the database if Selda couldn't make sense of the type.

• colIsAutoPrimary :: Bool

  Is the given column auto-incrementing?

• colIsNullable :: Bool

  Can the column be NULL?

• colHasIndex :: Bool

  Is the column explicitly indexed (i.e. using indexed)?

• colFKs :: [(TableName, ColName)]

  Any foreign key (table, column) pairs referenced by this column.

Instances

Show ColumnInfo

Defined in Database.Selda.Backend.Internal

Methods

showsPrec :: Int -> ColumnInfo -> ShowS

show :: ColumnInfo -> String

showList :: [ColumnInfo] -> ShowS

Eq ColumnInfo

Defined in Database.Selda.Backend.Internal

Methods

(==) :: ColumnInfo -> ColumnInfo -> Bool

(/=) :: ColumnInfo -> ColumnInfo -> Bool

tableInfo :: Table a -> TableInfo

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

fromColInfo :: ColInfo -> ColumnInfo

Convert a ColInfo into a ColumnInfo.

isAutoPrimary :: ColAttr -> Bool

isPrimary :: ColAttr -> Bool

isUnique :: ColAttr -> Bool

sqlDateTimeFormat :: String

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

sqlDateFormat :: String

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

sqlTimeFormat :: String

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

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

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

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

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

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

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

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

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

Get the backend in use by the computation.