TsWeb.Db

This builds on TsWeb.Types.Db's read-only/read-write discrimination by providing query functions to perform read-only operations, and an execute function to run updates, inserts, and deletes (and also selects as appropriate). All of these are performed as TsActionCtxT actions so as to nicely integrate with Spock. Finally, because I'm not a fan of exceptions, all of these functions trap Postgres errors and convert them into sum-type results.

I'm not yet providing shortcuts for the beam-postgres specific functions. I'm not actually sure that I need to (IIRC they all build Pg actions), but I will be adding them if necessary.

Documentation

data TxOpt

Transaction option: provide WithTx to wrap operations in BEGIN/COMMIT, or NoTx to skip that.

Constructors

NoTx

WithTx

Instances

Bounded TxOpt

Defined in TsWeb.Db

Methods

minBound :: TxOpt

maxBound :: TxOpt

Enum TxOpt

Defined in TsWeb.Db

Methods

succ :: TxOpt -> TxOpt

pred :: TxOpt -> TxOpt

toEnum :: Int -> TxOpt

fromEnum :: TxOpt -> Int

enumFrom :: TxOpt -> [TxOpt]

enumFromThen :: TxOpt -> TxOpt -> [TxOpt]

enumFromTo :: TxOpt -> TxOpt -> [TxOpt]

enumFromThenTo :: TxOpt -> TxOpt -> TxOpt -> [TxOpt]

Eq TxOpt

Defined in TsWeb.Db

Methods

(==) :: TxOpt -> TxOpt -> Bool

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

Ord TxOpt

Defined in TsWeb.Db

Methods

compare :: TxOpt -> TxOpt -> Ordering

(<) :: TxOpt -> TxOpt -> Bool

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

(>) :: TxOpt -> TxOpt -> Bool

(>=) :: TxOpt -> TxOpt -> Bool

max :: TxOpt -> TxOpt -> TxOpt

min :: TxOpt -> TxOpt -> TxOpt

Show TxOpt

Defined in TsWeb.Db

Methods

showsPrec :: Int -> TxOpt -> ShowS

show :: TxOpt -> String

showList :: [TxOpt] -> ShowS

data QueryResult a

Result of a select operation. This will either succeed with a QSimply, or fail with a QError (probably then an error in the db connection or table definitions).

Constructors

QSimply a

QError SqlError

Instances

Eq a => Eq (QueryResult a)

Defined in TsWeb.Db

Methods

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

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

Show a => Show (QueryResult a)

Defined in TsWeb.Db

Methods

showsPrec :: Int -> QueryResult a -> ShowS

show :: QueryResult a -> String

showList :: [QueryResult a] -> ShowS

data ExecResult a

The result of a select, insert, update, or delete operation. This adds a constraint error to the QueryResult, making it nicer to filter out conflicts when handling errors.

Constructors

ESimply a

EConstraint SqlError ConstraintViolation

EError SqlError

Instances

Eq a => Eq (ExecResult a)

Defined in TsWeb.Db

Methods

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

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

Show a => Show (ExecResult a)

Defined in TsWeb.Db

Methods

showsPrec :: Int -> ExecResult a -> ShowS

show :: ExecResult a -> String

showList :: [ExecResult a] -> ShowS

query :: ListContains n ReadOnlyPool xs => TxOpt -> RoPg a -> TsActionCtxT lts xs sessdata (QueryResult a)

Run one or many Beam runSelectReturningList or runSelectReturningOne operation(s) against a view's ReadOnlyPool.

queryMaybe :: (ListContains n ReadOnlyPool xs, FromBackendRow Postgres a) => Sel a -> TsActionCtxT lts xs sessdata (QueryResult (Maybe a))

Run a single Beam select, returning a single (Maybe) value

queryList :: (ListContains n ReadOnlyPool xs, FromBackendRow Postgres a) => Sel a -> TsActionCtxT lts xs sessdata (QueryResult [a])

Run a single Beam select, returning a list of values

execute :: ListContains n ReadWritePool xs => TxOpt -> Pg a -> TsActionCtxT lts xs sessdata (ExecResult a)

Run any arbitrary Pg monad in the context of a view, returning an ExecResult