Safe Haskell | None |
---|---|
Language | Haskell2010 |
- class MonadBase IO m => HasPostgres m where
- withPGConnection :: (Connection -> m a) -> m a
- class TransactionSafe m
- newtype PgMonadT m a = PgMonadT {
- unPgMonadT :: ReaderT Connection m a
- runPgMonadT :: Connection -> PgMonadT m a -> m a
- launchPG :: HasPostgres m => PgMonadT m a -> m a
- newtype InetText = InetText {
- unInetText :: Text
- newtype FN = FN [Text]
- textFN :: Text -> FN
- newtype MarkedRow = MR {
- unMR :: [(FN, SqlBuilder)]
- mrToBuilder :: SqlBuilder -> MarkedRow -> SqlBuilder
- class ToMarkedRow a where
- toMarkedRow :: a -> MarkedRow
Query execution
class MonadBase IO m => HasPostgres m where Source
Instances of this typeclass can acquire connection and pass it to computation. It can be reader of pool of connections or just reader of connection
withPGConnection :: (Connection -> m a) -> m a Source
HasPostgres m => HasPostgres (IdentityT m) Source | |
HasPostgres m => HasPostgres (MaybeT m) Source | |
MonadBase IO m => HasPostgres (PgMonadT m) Source | |
(HasPostgres m, Monoid w) => HasPostgres (WriterT w m) Source | |
(HasPostgres m, Monoid w) => HasPostgres (WriterT w m) Source | |
HasPostgres m => HasPostgres (StateT s m) Source | |
HasPostgres m => HasPostgres (StateT s m) Source | |
HasPostgres m => HasPostgres (ReaderT r m) Source | |
HasPostgres m => HasPostgres (EitherT e m) Source | |
(MonadBase IO m, MonadBaseControl IO m, HGettable els (Pool Connection)) => HasPostgres (HReaderT els m) Source | |
HasPostgres m => HasPostgres (ContT r m) Source | |
HasPostgres m => HasPostgres (ExceptT e m) Source |
class TransactionSafe m Source
Empty typeclass signing monad in which transaction is
safe. i.e. PgMonadT
have this instance, but some other monad giving
connection from e.g. connection pool is not.
TransactionSafe m => TransactionSafe (IdentityT m) Source | |
TransactionSafe m => TransactionSafe (MaybeT m) Source | |
TransactionSafe (PgMonadT m) Source | |
(TransactionSafe m, Monoid w) => TransactionSafe (WriterT w m) Source | |
(TransactionSafe m, Monoid w) => TransactionSafe (WriterT w m) Source | |
TransactionSafe m => TransactionSafe (StateT s m) Source | |
TransactionSafe m => TransactionSafe (StateT s m) Source | |
TransactionSafe m => TransactionSafe (ReaderT r m) Source | |
TransactionSafe m => TransactionSafe (EitherT e m) Source | |
TransactionSafe m => TransactionSafe (ContT r m) Source | |
TransactionSafe m => TransactionSafe (ExceptT e m) Source |
Reader of connection. Has instance of HasPostgres
. So if you have a
connection you can run queries in this monad using runPgMonadT
. Or you
can use this transformer to run sequence of queries using same
connection with launchPG
.
PgMonadT | |
|
runPgMonadT :: Connection -> PgMonadT m a -> m a Source
launchPG :: HasPostgres m => PgMonadT m a -> m a Source
If your monad have instance of HasPostgres
you maybe dont need this
function, unless your instance use withPGPool
which acquires connection
from pool for each query. If you want to run sequence of queries using same
connection you need this function
Auxiliary types
type to put and get from db inet
and cidr
typed postgresql
fields. This should be in postgresql-simple in fact.
Dot-separated field name. Each element in nested list will be
properly quoted and separated by dot. It also have instance of
ToSqlBuilder
and IsString
so you can:
>>>
let a = "hello" :: FN
>>>
a
FN ["hello"]
>>>
let b = "user.name" :: FN
>>>
b
FN ["user","name"]
>>>
let n = "u.name" :: FN
>>>
runSqlBuilder c $ toSqlBuilder n
"\"u\".\"name\""
>>>
("user" <> "name") :: FN
FN ["user","name"]
>>>
let a = "name" :: FN
>>>
let b = "email" :: FN
>>>
runSqlBuilder c [sqlExp|^{"u" <> a} = 'name', ^{"e" <> b} = 'email'|]
"\"u\".\"name\" = 'name', \"e\".\"email\" = 'email'"
Marked row is list of pairs of field name and some sql expression. Used to generate queries like:
name = name
AND size = 10 AND length = 20
or
UPDATE tbl SET name = name
, size = 10, lenght = 20
MR | |
|
:: SqlBuilder | Builder to intercalate with |
-> MarkedRow | |
-> SqlBuilder |
Turns marked row to query intercalating it with other builder
>>>
runSqlBuilder c $ mrToBuilder "AND" $ MR [("name", mkValue "petr"), ("email", mkValue "foo@bar.com")]
" \"name\" = 'petr' AND \"email\" = 'foo@bar.com' "
class ToMarkedRow a where Source
toMarkedRow :: a -> MarkedRow Source
generate list of pairs (field name, field value)