| Safe Haskell | None |
|---|---|
| Language | Haskell2010 |
Database.Beam.Postgres
Contents
- Beam Postgres backend
- Beam URI support
- Postgres-specific features
postgresql-simplere-exports
Description
Postgres is a popular, open-source RDBMS. It is fairly standards compliant and supports many advanced features and data types.
The beam-postgres module is built atop of postgresql-simple, which is
used for connection management, transaction support, serialization, and
deserialization.
beam-postgres supports most beam features as well as many postgres-specific
features. For example, beam-postgres provides support for full-text search,
DISTINCT ON, JSON handling, postgres ARRAYs, RANGEs, and the MONEY type.
The documentation for beam-postgres functionality below indicates which
postgres function each function or type wraps. Postgres maintains its own
in-depth documentation. Please refer to that for more detailed information on
behavior.
For examples on how to use beam-postgres usage, see
its manual.
Synopsis
- data Postgres = Postgres
- data Pg a
- liftIOWithHandle :: (Connection -> IO a) -> Pg a
- data PgCommandSyntax
- data PgSyntax
- data PgSelectSyntax
- data PgInsertSyntax
- data PgUpdateSyntax
- data PgDeleteSyntax
- postgresUriSyntax :: c Postgres Connection Pg -> BeamURIOpeners c
- json :: (ToJSON a, FromJSON a) => DataType Postgres (PgJSON a)
- jsonb :: (ToJSON a, FromJSON a) => DataType Postgres (PgJSONB a)
- uuid :: DataType Postgres UUID
- money :: DataType Postgres PgMoney
- tsquery :: DataType Postgres TsQuery
- tsvector :: DataType Postgres TsVector
- text :: DataType Postgres Text
- bytea :: DataType Postgres ByteString
- unboundedArray :: forall a. Typeable a => DataType Postgres a -> DataType Postgres (Vector a)
- smallserial :: Integral a => DataType Postgres (SqlSerial a)
- serial :: Integral a => DataType Postgres (SqlSerial a)
- bigserial :: Integral a => DataType Postgres (SqlSerial a)
- data TsVectorConfig
- newtype TsVector = TsVector ByteString
- toTsVector :: BeamSqlBackendIsString Postgres str => Maybe TsVectorConfig -> QGenExpr context Postgres s str -> QGenExpr context Postgres s TsVector
- english :: TsVectorConfig
- newtype TsQuery = TsQuery ByteString
- (@@) :: QGenExpr context Postgres s TsVector -> QGenExpr context Postgres s TsQuery -> QGenExpr context Postgres s Bool
- toTsQuery :: BeamSqlBackendIsString Postgres str => Maybe TsVectorConfig -> QGenExpr context Postgres s str -> QGenExpr context Postgres s TsQuery
- newtype PgJSON a = PgJSON a
- newtype PgJSONB a = PgJSONB a
- class IsPgJSON (json :: * -> *) where
- pgJsonEach :: QGenExpr ctxt Postgres s (json a) -> QGenExpr ctxt Postgres s (PgSetOf (PgJSONEach (json Value)))
- pgJsonEachText :: QGenExpr ctxt Postgres s (json a) -> QGenExpr ctxt Postgres s (PgSetOf (PgJSONEach Text))
- pgJsonKeys :: QGenExpr ctxt Postgres s (json a) -> QGenExpr ctxt Postgres s (PgSetOf PgJSONKey)
- pgJsonArrayElements :: QGenExpr ctxt Postgres s (json a) -> QGenExpr ctxt Postgres s (PgSetOf (PgJSONElement (json Value)))
- pgJsonArrayElementsText :: QGenExpr ctxt Postgres s (json a) -> QGenExpr ctxt Postgres s (PgSetOf (PgJSONElement Text))
- pgJsonTypeOf :: QGenExpr ctxt Postgres s (json a) -> QGenExpr ctxt Postgres s Text
- pgJsonStripNulls :: QGenExpr ctxt Postgres s (json a) -> QGenExpr ctxt Postgres s (json b)
- pgJsonAgg :: QExpr Postgres s a -> QAgg Postgres s (json a)
- pgJsonObjectAgg :: QExpr Postgres s key -> QExpr Postgres s value -> QAgg Postgres s (json a)
- data PgJSONEach valType f = PgJSONEach {
- pgJsonEachKey :: C f Text
- pgJsonEachValue :: C f valType
- data PgJSONKey f = PgJSONKey {}
- data PgJSONElement a f = PgJSONElement {
- pgJsonElement :: C f a
- (@>) :: QGenExpr ctxt Postgres s (PgJSONB a) -> QGenExpr ctxt Postgres s (PgJSONB b) -> QGenExpr ctxt Postgres s Bool
- (<@) :: QGenExpr ctxt Postgres s (PgJSONB a) -> QGenExpr ctxt Postgres s (PgJSONB b) -> QGenExpr ctxt Postgres s Bool
- (->#) :: IsPgJSON json => QGenExpr ctxt Postgres s (json a) -> QGenExpr ctxt Postgres s Int32 -> QGenExpr ctxt Postgres s (json b)
- (->$) :: IsPgJSON json => QGenExpr ctxt Postgres s (json a) -> QGenExpr ctxt Postgres s Text -> QGenExpr ctxt Postgres s (json b)
- (->>#) :: IsPgJSON json => QGenExpr ctxt Postgres s (json a) -> QGenExpr ctxt Postgres s Int32 -> QGenExpr ctxt Postgres s Text
- (->>$) :: IsPgJSON json => QGenExpr ctxt Postgres s (json a) -> QGenExpr ctxt Postgres s Text -> QGenExpr ctxt Postgres s Text
- (#>) :: IsPgJSON json => QGenExpr ctxt Postgres s (json a) -> QGenExpr ctxt Postgres s (Vector Text) -> QGenExpr ctxt Postgres s (json b)
- (#>>) :: IsPgJSON json => QGenExpr ctxt Postgres s (json a) -> QGenExpr ctxt Postgres s (Vector Text) -> QGenExpr ctxt Postgres s Text
- (?) :: QGenExpr ctxt Postgres s (PgJSONB a) -> QGenExpr ctxt Postgres s Text -> QGenExpr ctxt Postgres s Bool
- (?|) :: QGenExpr ctxt Postgres s (PgJSONB a) -> QGenExpr ctxt Postgres s (Vector Text) -> QGenExpr ctxt Postgres s Bool
- (?&) :: QGenExpr ctxt Postgres s (PgJSONB a) -> QGenExpr ctxt Postgres s (Vector Text) -> QGenExpr ctxt Postgres s Bool
- withoutKey :: QGenExpr ctxt Postgres s (PgJSONB a) -> QGenExpr ctxt Postgres s Text -> QGenExpr ctxt Postgres s (PgJSONB b)
- withoutIdx :: QGenExpr ctxt Postgres s (PgJSONB a) -> QGenExpr ctxt Postgres s Int32 -> QGenExpr ctxt Postgres s (PgJSONB b)
- withoutKeys :: QGenExpr ctxt Postgres s (PgJSONB a) -> QGenExpr ctxt Postgres s (Vector Text) -> QGenExpr ctxt Postgres s (PgJSONB b)
- pgJsonArrayLength :: IsPgJSON json => QGenExpr ctxt Postgres s (json a) -> QGenExpr ctxt Postgres s Int32
- pgArrayToJson :: QGenExpr ctxt Postgres s (Vector e) -> QGenExpr ctxt Postgres s (PgJSON a)
- pgJsonbUpdate :: QGenExpr ctxt Postgres s (PgJSONB a) -> QGenExpr ctxt Postgres s (Vector Text) -> QGenExpr ctxt Postgres s (PgJSONB b) -> QGenExpr ctxt Postgres s (PgJSONB a)
- pgJsonbSet :: QGenExpr ctxt Postgres s (PgJSONB a) -> QGenExpr ctxt Postgres s (Vector Text) -> QGenExpr ctxt Postgres s (PgJSONB b) -> QGenExpr ctxt Postgres s (PgJSONB a)
- pgJsonbPretty :: QGenExpr ctxt Postgres s (PgJSONB a) -> QGenExpr ctxt Postgres s Text
- newtype PgMoney = PgMoney {}
- pgMoney :: Real a => a -> PgMoney
- pgScaleMoney_ :: Num a => QGenExpr context Postgres s a -> QGenExpr context Postgres s PgMoney -> QGenExpr context Postgres s PgMoney
- pgDivideMoney_ :: Num a => QGenExpr context Postgres s PgMoney -> QGenExpr context Postgres s a -> QGenExpr context Postgres s PgMoney
- pgDivideMoneys_ :: Num a => QGenExpr context Postgres s PgMoney -> QGenExpr context Postgres s PgMoney -> QGenExpr context Postgres s a
- pgAddMoney_ :: QGenExpr context Postgres s PgMoney -> QGenExpr context Postgres s PgMoney -> QGenExpr context Postgres s PgMoney
- pgSubtractMoney_ :: QGenExpr context Postgres s PgMoney -> QGenExpr context Postgres s PgMoney -> QGenExpr context Postgres s PgMoney
- pgSumMoneyOver_ :: Maybe PgAggregationSetQuantifierSyntax -> QExpr Postgres s PgMoney -> QExpr Postgres s PgMoney
- pgAvgMoneyOver_ :: Maybe PgAggregationSetQuantifierSyntax -> QExpr Postgres s PgMoney -> QExpr Postgres s PgMoney
- pgSumMoney_ :: QExpr Postgres s PgMoney -> QExpr Postgres s PgMoney
- pgAvgMoney_ :: QExpr Postgres s PgMoney -> QExpr Postgres s PgMoney
- data PgPoint = PgPoint !Double !Double
- data PgLine = PgLine !Double !Double !Double
- data PgLineSegment = PgLineSegment !PgPoint !PgPoint
- data PgBox = PgBox !PgPoint !PgPoint
- data PgPath
- data PgPolygon = PgPolygon (NonEmpty PgPoint)
- data PgCircle = PgCircle !PgPoint !Double
- newtype PgRegex = PgRegex Text
- pgRegex_ :: BeamSqlBackendIsString Postgres text => QGenExpr ctxt Postgres s text -> QGenExpr ctxt Postgres s PgRegex
- (~.) :: BeamSqlBackendIsString Postgres text => QGenExpr ctxt Postgres s text -> QGenExpr ctxt Postgres s PgRegex -> QGenExpr ctxt Postgres s Bool
- (~*.) :: BeamSqlBackendIsString Postgres text => QGenExpr ctxt Postgres s text -> QGenExpr ctxt Postgres s PgRegex -> QGenExpr ctxt Postgres s Bool
- (!~.) :: BeamSqlBackendIsString Postgres text => QGenExpr ctxt Postgres s text -> QGenExpr ctxt Postgres s PgRegex -> QGenExpr ctxt Postgres s Bool
- (!~*.) :: BeamSqlBackendIsString Postgres text => QGenExpr ctxt Postgres s text -> QGenExpr ctxt Postgres s PgRegex -> QGenExpr ctxt Postgres s Bool
- pgRegexpReplace_ :: BeamSqlBackendIsString Postgres text => QGenExpr ctxt Postgres s text -> QGenExpr ctxt Postgres s PgRegex -> QGenExpr ctxt Postgres s text -> QGenExpr ctxt Postgres s Text -> QGenExpr ctxt Postgres s txt
- pgRegexpMatch_ :: BeamSqlBackendIsString Postgres text => QGenExpr ctxt Postgres s text -> QGenExpr ctxt Postgres s PgRegex -> QGenExpr ctxt Postgres s (Maybe (Vector text))
- pgRegexpSplitToTable :: BeamSqlBackendIsString Postgres text => QGenExpr ctxt Postgres s text -> QGenExpr ctxt Postgres s PgRegex -> Q Postgres db s (QExpr Postgres s Text)
- pgRegexpSplitToArray :: BeamSqlBackendIsString Postgres text => QGenExpr ctxt Postgres s text -> QGenExpr ctxt Postgres s PgRegex -> QGenExpr ctxt Postgres s (Vector text)
- data PgSetOf (tbl :: (* -> *) -> *)
- pgUnnest :: forall tbl db s. Beamable tbl => QExpr Postgres s (PgSetOf tbl) -> Q Postgres db s (QExprTable Postgres s tbl)
- pgUnnestArray :: QExpr Postgres s (Vector a) -> Q Postgres db s (QExpr Postgres s a)
- pgUnnestArrayWithOrdinality :: QExpr Postgres s (Vector a) -> Q Postgres db s (QExpr Postgres s Int64, QExpr Postgres s a)
- data PgArrayValueContext
- class PgIsArrayContext ctxt
- array_ :: forall context f s a. (PgIsArrayContext context, Foldable f) => f (QGenExpr context Postgres s a) -> QGenExpr context Postgres s (Vector a)
- arrayOf_ :: Q Postgres db s (QExpr Postgres s a) -> QGenExpr context Postgres s (Vector a)
- (++.) :: QGenExpr ctxt Postgres s (Vector a) -> QGenExpr ctxt Postgres s (Vector a) -> QGenExpr ctxt Postgres s (Vector a)
- pgArrayAgg :: QExpr Postgres s a -> QAgg Postgres s (Vector a)
- pgArrayAggOver :: Maybe PgAggregationSetQuantifierSyntax -> QExpr Postgres s a -> QAgg Postgres s (Vector a)
- (!.) :: Integral ix => QGenExpr context Postgres s (Vector a) -> QGenExpr context Postgres s ix -> QGenExpr context Postgres s a
- arrayDims_ :: BeamSqlBackendIsString Postgres text => QGenExpr context Postgres s (Vector a) -> QGenExpr context Postgres s text
- arrayUpper_ :: forall (dim :: Nat) context num v s. (KnownNat dim, WithinBounds dim (Vector v), Integral num) => QGenExpr context Postgres s (Vector v) -> QGenExpr context Postgres s num
- arrayLower_ :: forall (dim :: Nat) context num v s. (KnownNat dim, WithinBounds dim (Vector v), Integral num) => QGenExpr context Postgres s (Vector v) -> QGenExpr context Postgres s num
- arrayUpperUnsafe_ :: (Integral dim, Integral length) => QGenExpr context Postgres s (Vector v) -> QGenExpr context Postgres s dim -> QGenExpr context Postgres s (Maybe length)
- arrayLowerUnsafe_ :: (Integral dim, Integral length) => QGenExpr context Postgres s (Vector v) -> QGenExpr context Postgres s dim -> QGenExpr context Postgres s (Maybe length)
- arrayLength_ :: forall (dim :: Nat) ctxt num v s. (KnownNat dim, WithinBounds dim (Vector v), Integral num) => QGenExpr ctxt Postgres s (Vector v) -> QGenExpr ctxt Postgres s num
- arrayLengthUnsafe_ :: (Integral dim, Integral num) => QGenExpr ctxt Postgres s (Vector v) -> QGenExpr ctxt Postgres s dim -> QGenExpr ctxt Postgres s (Maybe num)
- isSupersetOf_ :: QGenExpr ctxt Postgres s (Vector a) -> QGenExpr ctxt Postgres s (Vector a) -> QGenExpr ctxt Postgres s Bool
- isSubsetOf_ :: QGenExpr ctxt Postgres s (Vector a) -> QGenExpr ctxt Postgres s (Vector a) -> QGenExpr ctxt Postgres s Bool
- data PgRange (n :: *) a
- = PgEmptyRange
- | PgRange (PgRangeBound a) (PgRangeBound a)
- data PgRangeBound a = PgRangeBound PgBoundType (Maybe a)
- data PgBoundType
- class PgIsRange n where
- data PgInt4Range
- data PgInt8Range
- data PgNumRange
- data PgTsRange
- data PgTsTzRange
- data PgDateRange
- range_ :: forall n a context s. PgIsRange n => PgBoundType -> PgBoundType -> QGenExpr context Postgres s (Maybe a) -> QGenExpr context Postgres s (Maybe a) -> QGenExpr context Postgres s (PgRange n a)
- inclusive :: a -> PgRangeBound a
- exclusive :: a -> PgRangeBound a
- unbounded :: PgRangeBound a
- (-@>-) :: QGenExpr context Postgres s (PgRange n a) -> QGenExpr context Postgres s (PgRange n a) -> QGenExpr context Postgres s Bool
- (-@>) :: QGenExpr context Postgres s (PgRange n a) -> QGenExpr context Postgres s a -> QGenExpr context Postgres s Bool
- (-<@-) :: QGenExpr context Postgres s (PgRange n a) -> QGenExpr context Postgres s (PgRange n a) -> QGenExpr context Postgres s Bool
- (<@-) :: QGenExpr context Postgres s a -> QGenExpr context Postgres s (PgRange n a) -> QGenExpr context Postgres s Bool
- (-&&-) :: QGenExpr context Postgres s (PgRange n a) -> QGenExpr context Postgres s (PgRange n a) -> QGenExpr context Postgres s Bool
- (-<<-) :: QGenExpr context Postgres s (PgRange n a) -> QGenExpr context Postgres s (PgRange n a) -> QGenExpr context Postgres s Bool
- (->>-) :: QGenExpr context Postgres s (PgRange n a) -> QGenExpr context Postgres s (PgRange n a) -> QGenExpr context Postgres s Bool
- (-&<-) :: QGenExpr context Postgres s (PgRange n a) -> QGenExpr context Postgres s (PgRange n a) -> QGenExpr context Postgres s Bool
- (-&>-) :: QGenExpr context Postgres s (PgRange n a) -> QGenExpr context Postgres s (PgRange n a) -> QGenExpr context Postgres s Bool
- (--|--) :: QGenExpr context Postgres s (PgRange n a) -> QGenExpr context Postgres s (PgRange n a) -> QGenExpr context Postgres s Bool
- (-+-) :: QGenExpr context Postgres s (PgRange n a) -> QGenExpr context Postgres s (PgRange n a) -> QGenExpr context Postgres s (PgRange n a)
- (-*-) :: QGenExpr context Postgres s (PgRange n a) -> QGenExpr context Postgres s (PgRange n a) -> QGenExpr context Postgres s (PgRange n a)
- (-.-) :: QGenExpr context Postgres s (PgRange n a) -> QGenExpr context Postgres s (PgRange n a) -> QGenExpr context Postgres s (PgRange n a)
- rLower_ :: QGenExpr context Postgres s (PgRange n a) -> QGenExpr context Postgres s (Maybe a)
- rUpper_ :: QGenExpr context Postgres s (PgRange n a) -> QGenExpr context Postgres s (Maybe a)
- isEmpty_ :: QGenExpr context Postgres s (PgRange n a) -> QGenExpr context Postgres s Bool
- lowerInc_ :: QGenExpr context Postgres s (PgRange n a) -> QGenExpr context Postgres s Bool
- upperInc_ :: QGenExpr context Postgres s (PgRange n a) -> QGenExpr context Postgres s Bool
- lowerInf_ :: QGenExpr context Postgres s (PgRange n a) -> QGenExpr context Postgres s Bool
- upperInf_ :: QGenExpr context Postgres s (PgRange n a) -> QGenExpr context Postgres s Bool
- rangeMerge_ :: QGenExpr context Postgres s (PgRange n a) -> QGenExpr context Postgres s (PgRange n a) -> QGenExpr context Postgres s (PgRange n a)
- pgBoolOr :: QExpr Postgres s a -> QAgg Postgres s (Maybe Bool)
- pgBoolAnd :: QExpr Postgres s a -> QAgg Postgres s (Maybe Bool)
- pgStringAgg :: BeamSqlBackendIsString Postgres str => QExpr Postgres s str -> QExpr Postgres s str -> QAgg Postgres s (Maybe str)
- pgStringAggOver :: BeamSqlBackendIsString Postgres str => Maybe PgAggregationSetQuantifierSyntax -> QExpr Postgres s str -> QExpr Postgres s str -> QAgg Postgres s (Maybe str)
- pgNubBy_ :: (Projectible Postgres key, Projectible Postgres r) => (r -> key) -> Q Postgres db s r -> Q Postgres db s r
- now_ :: QExpr Postgres s LocalTime
- ilike_ :: BeamSqlBackendIsString Postgres text => QExpr Postgres s text -> QExpr Postgres s text -> QExpr Postgres s Bool
- runBeamPostgres :: Connection -> Pg a -> IO a
- runBeamPostgresDebug :: (String -> IO ()) -> Connection -> Pg a -> IO a
- data PgExtensionEntity extension
- class IsPgExtension extension where
- pgExtensionName :: Proxy extension -> Text
- pgExtensionBuild :: extension
- pgCreateExtension :: forall extension db. IsPgExtension extension => Migration Postgres (CheckedDatabaseEntity Postgres db (PgExtensionEntity extension))
- pgDropExtension :: forall extension. CheckedDatabaseEntityDescriptor Postgres (PgExtensionEntity extension) -> Migration Postgres ()
- getPgExtension :: DatabaseEntity Postgres db (PgExtensionEntity extension) -> extension
- fromPgIntegral :: forall a. (FromField a, Integral a, Typeable a) => FromBackendRowM Postgres a
- fromPgScientificOrIntegral :: (Bounded a, Integral a) => FromBackendRowM Postgres a
- class PgDebugStmt statement
- pgTraceStmtIO :: PgDebugStmt statement => Connection -> statement -> IO ()
- pgTraceStmtIO' :: PgDebugStmt statement => Connection -> statement -> IO ByteString
- pgTraceStmt :: PgDebugStmt statement => statement -> Pg ()
- data ResultError
- = Incompatible { }
- | UnexpectedNull { }
- | ConversionFailed { }
- data SqlError = SqlError {}
- data Connection
- data ConnectInfo = ConnectInfo {}
- defaultConnectInfo :: ConnectInfo
- connectPostgreSQL :: ByteString -> IO Connection
- connect :: ConnectInfo -> IO Connection
- close :: Connection -> IO ()
Beam Postgres backend
The Postgres backend type, used to parameterize MonadBeam. See the
definitions there for more information. The corresponding query monad is
Pg. See documentation for MonadBeam and the
user guide for more information on using
this backend.
Constructors
| Postgres |
Instances
MonadBeam in which we can run Postgres commands. See the documentation
for MonadBeam on examples of how to use.
beam-postgres also provides functions that let you run queries without
MonadBeam. These functions may be more efficient and offer a conduit
API. See Database.Beam.Postgres.Conduit for more information.
Instances
liftIOWithHandle :: (Connection -> IO a) -> Pg a Source #
Postgres syntax
data PgCommandSyntax Source #
Representation of an arbitrary Postgres command. This is the combination of
the command syntax (repesented by PgSyntax), as well as the type of command
(represented by PgCommandType). The command type is necessary for us to
know how to retrieve results from the database.
Instances
| IsSql92Syntax PgCommandSyntax Source # | |
Defined in Database.Beam.Postgres.Syntax Associated Types type Sql92SelectSyntax PgCommandSyntax # type Sql92InsertSyntax PgCommandSyntax # | |
| IsSql92DdlCommandSyntax PgCommandSyntax Source # | |
Defined in Database.Beam.Postgres.Syntax Associated Types type Sql92DdlCommandCreateTableSyntax PgCommandSyntax # | |
| type Sql92DeleteSyntax PgCommandSyntax Source # | |
Defined in Database.Beam.Postgres.Syntax | |
| type Sql92UpdateSyntax PgCommandSyntax Source # | |
Defined in Database.Beam.Postgres.Syntax | |
| type Sql92InsertSyntax PgCommandSyntax Source # | |
Defined in Database.Beam.Postgres.Syntax | |
| type Sql92SelectSyntax PgCommandSyntax Source # | |
Defined in Database.Beam.Postgres.Syntax | |
| type Sql92DdlCommandDropTableSyntax PgCommandSyntax Source # | |
| type Sql92DdlCommandAlterTableSyntax PgCommandSyntax Source # | |
| type Sql92DdlCommandCreateTableSyntax PgCommandSyntax Source # | |
A piece of Postgres SQL syntax, which may contain embedded escaped byte and
text sequences. PgSyntax composes monoidally, and may be created with
emit, emitBuilder, escapeString, escapBytea, and escapeIdentifier.
data PgSelectSyntax Source #
IsSql92SelectSyntax for Postgres
Instances
| IsSql99CommonTableExpressionSelectSyntax PgSelectSyntax Source # | |
Defined in Database.Beam.Postgres.Syntax Associated Types Methods withSyntax :: [Sql99SelectCTESyntax PgSelectSyntax] -> PgSelectSyntax -> PgSelectSyntax # | |
| IsSql99RecursiveCommonTableExpressionSelectSyntax PgSelectSyntax Source # | |
Defined in Database.Beam.Postgres.Syntax Methods withRecursiveSyntax :: [Sql99SelectCTESyntax PgSelectSyntax] -> PgSelectSyntax -> PgSelectSyntax # | |
| IsSql92SelectSyntax PgSelectSyntax Source # | |
Defined in Database.Beam.Postgres.Syntax Associated Types Methods selectStmt :: Sql92SelectSelectTableSyntax PgSelectSyntax -> [Sql92SelectOrderingSyntax PgSelectSyntax] -> Maybe Integer -> Maybe Integer -> PgSelectSyntax # | |
| type Sql99SelectCTESyntax PgSelectSyntax Source # | |
Defined in Database.Beam.Postgres.Syntax | |
| type Sql92SelectOrderingSyntax PgSelectSyntax Source # | |
Defined in Database.Beam.Postgres.Syntax | |
| type Sql92SelectSelectTableSyntax PgSelectSyntax Source # | |
Defined in Database.Beam.Postgres.Syntax | |
data PgInsertSyntax Source #
IsSql92InsertSyntax for Postgres
Instances
| IsSql92InsertSyntax PgInsertSyntax Source # | |
Defined in Database.Beam.Postgres.Syntax Associated Types Methods insertStmt :: Sql92InsertTableNameSyntax PgInsertSyntax -> [Text] -> Sql92InsertValuesSyntax PgInsertSyntax -> PgInsertSyntax # | |
| type Sql92InsertTableNameSyntax PgInsertSyntax Source # | |
| type Sql92InsertValuesSyntax PgInsertSyntax Source # | |
data PgUpdateSyntax Source #
IsSql92UpdateSyntax for Postgres
Instances
| IsSql92UpdateSyntax PgUpdateSyntax Source # | |
Defined in Database.Beam.Postgres.Syntax Associated Types type Sql92UpdateTableNameSyntax PgUpdateSyntax # | |
| type Sql92UpdateExpressionSyntax PgUpdateSyntax Source # | |
| type Sql92UpdateFieldNameSyntax PgUpdateSyntax Source # | |
| type Sql92UpdateTableNameSyntax PgUpdateSyntax Source # | |
data PgDeleteSyntax Source #
IsSql92DeleteSyntax for Postgres
Instances
| IsSql92DeleteSyntax PgDeleteSyntax Source # | |
Defined in Database.Beam.Postgres.Syntax Associated Types | |
| type Sql92DeleteExpressionSyntax PgDeleteSyntax Source # | |
| type Sql92DeleteTableNameSyntax PgDeleteSyntax Source # | |
Beam URI support
postgresUriSyntax :: c Postgres Connection Pg -> BeamURIOpeners c Source #
BeamURIOpeners for the standard postgresql: URI scheme. See the
postgres documentation for more details on the formatting. See documentation
for BeamURIOpeners for more information on how to use this with beam
Postgres-specific features
Postgres-specific data types
uuid :: DataType Postgres UUID Source #
DataType for UUID columns. The pgCryptoGenRandomUUID function in
the PgCrypto extension can be used to generate UUIDs at random.
text :: DataType Postgres Text Source #
DataType for Postgres TEXT. characterLargeObject is also mapped to
this data type
bytea :: DataType Postgres ByteString Source #
DataType for Postgres BYTEA. binaryLargeObject is also mapped to
this data type
unboundedArray :: forall a. Typeable a => DataType Postgres a -> DataType Postgres (Vector a) Source #
DataType for a Postgres array without any bounds.
Note that array support in beam-migrate is still incomplete.
SERIAL support
smallserial :: Integral a => DataType Postgres (SqlSerial a) Source #
Postgres SERIAL data types. Automatically generates an appropriate
DEFAULT clause and sequence
serial :: Integral a => DataType Postgres (SqlSerial a) Source #
Postgres SERIAL data types. Automatically generates an appropriate
DEFAULT clause and sequence
bigserial :: Integral a => DataType Postgres (SqlSerial a) Source #
Postgres SERIAL data types. Automatically generates an appropriate
DEFAULT clause and sequence
Full-text search
Postgres has comprehensive, and thus complicated, support for full text search. The types and functions in this section map closely to the underlying Postgres API, which is described in the documentation.
TSVECTOR data type
data TsVectorConfig Source #
The identifier of a Postgres text search configuration.
Use the IsString instance to construct new values of this type
Instances
The type of a document preprocessed for full-text search. The contained
ByteString is the Postgres representation of the TSVECTOR type. Use
toTsVector to construct these on-the-fly from strings.
When this field is embedded in a beam table, defaultMigratableDbSettings
will give the column the postgres TSVECTOR type.
Constructors
| TsVector ByteString |
Instances
toTsVector :: BeamSqlBackendIsString Postgres str => Maybe TsVectorConfig -> QGenExpr context Postgres s str -> QGenExpr context Postgres s TsVector Source #
The Postgres to_tsvector function. Given a configuration and string,
return the TSVECTOR that represents the contents of the string.
english :: TsVectorConfig Source #
A full-text search configuration with sensible defaults for english
TSQUERY data type
A query that can be run against a document contained in a TsVector.
When this field is embedded in a beam table, defaultMigratableDbSettings
will give the column the postgres TSVECTOR type
Constructors
| TsQuery ByteString |
Instances
(@@) :: QGenExpr context Postgres s TsVector -> QGenExpr context Postgres s TsQuery -> QGenExpr context Postgres s Bool Source #
Determine if the given TSQUERY matches the document represented by the
TSVECTOR. Behaves exactly like the similarly-named operator in postgres.
toTsQuery :: BeamSqlBackendIsString Postgres str => Maybe TsVectorConfig -> QGenExpr context Postgres s str -> QGenExpr context Postgres s TsQuery Source #
The Postgres to_tsquery function. Given a configuration and string,
return the TSQUERY that represents the contents of the string.
JSON and JSONB data types
Postgres supports storing JSON in columns, as either a text-based type
(JSON) or a specialized binary encoding (JSONB). beam-postgres
accordingly provides the PgJSON and PgJSONB data types. Each of these
types takes a type parameter indicating the Haskell object represented by the
JSON object stored in the column. In order for serialization to work, be sure
to provide FromJSON and ToJSON instances for this type. If you do not
know the shape of the data stored, substitute Value for this type
parameter.
For more information on Postgres JSON support see the postgres manual.
The Postgres JSON type, which stores textual values that represent JSON
objects. The type parameter indicates the Haskell type which the JSON
encodes. This type must be a member of FromJSON and ToJSON in order for
deserialization and serialization to work as expected.
The defaultMigratableDbSettings function automatically assigns the postgres
JSON type to fields with this type.
Constructors
| PgJSON a |
Instances
The Postgres JSONB type, which stores JSON-encoded data in a
postgres-specific binary format. Like PgJSON, the type parameter indicates
the Haskell type which the JSON encodes.
Fields with this type are automatically given the Postgres JSONB type
Constructors
| PgJSONB a |
Instances
class IsPgJSON (json :: * -> *) where Source #
Postgres provides separate json_ and jsonb_ functions. However, we know
what we're dealing with based on the type of data, so we can be less obtuse.
For more information on how these functions behave, see the Postgres manual section on JSON.
Methods
pgJsonEach :: QGenExpr ctxt Postgres s (json a) -> QGenExpr ctxt Postgres s (PgSetOf (PgJSONEach (json Value))) Source #
The json_each or jsonb_each function. Values returned as json or
jsonb respectively. Use pgUnnest to join against the result
pgJsonEachText :: QGenExpr ctxt Postgres s (json a) -> QGenExpr ctxt Postgres s (PgSetOf (PgJSONEach Text)) Source #
Like pgJsonEach, but returning text values instead
pgJsonKeys :: QGenExpr ctxt Postgres s (json a) -> QGenExpr ctxt Postgres s (PgSetOf PgJSONKey) Source #
The json_object_keys and jsonb_object_keys function. Use pgUnnest
to join against the result.
pgJsonArrayElements :: QGenExpr ctxt Postgres s (json a) -> QGenExpr ctxt Postgres s (PgSetOf (PgJSONElement (json Value))) Source #
The json_array_elements and jsonb_array_elements function. Use
pgUnnest to join against the result
pgJsonArrayElementsText :: QGenExpr ctxt Postgres s (json a) -> QGenExpr ctxt Postgres s (PgSetOf (PgJSONElement Text)) Source #
Like pgJsonArrayElements, but returning the values as Text
pgJsonTypeOf :: QGenExpr ctxt Postgres s (json a) -> QGenExpr ctxt Postgres s Text Source #
The json_typeof or jsonb_typeof function
pgJsonStripNulls :: QGenExpr ctxt Postgres s (json a) -> QGenExpr ctxt Postgres s (json b) Source #
The json_strip_nulls or jsonb_strip_nulls function.
pgJsonAgg :: QExpr Postgres s a -> QAgg Postgres s (json a) Source #
The json_agg or jsonb_agg aggregate.
pgJsonObjectAgg :: QExpr Postgres s key -> QExpr Postgres s value -> QAgg Postgres s (json a) Source #
The json_object_agg or jsonb_object_agg. The first argument gives the
key source and the second the corresponding values.
Instances
data PgJSONEach valType f Source #
Key-value pair, used as output of pgJsonEachText and pgJsonEach
Constructors
| PgJSONEach | |
Fields
| |
Instances
| Beamable (PgJSONEach valType) Source # | |
Defined in Database.Beam.Postgres.PgSpecific Methods zipBeamFieldsM :: forall m (f :: Type -> Type) (g :: Type -> Type) (h :: Type -> Type). Applicative m => (forall a. Columnar' f a -> Columnar' g a -> m (Columnar' h a)) -> PgJSONEach valType f -> PgJSONEach valType g -> m (PgJSONEach valType h) # tblSkeleton :: TableSkeleton (PgJSONEach valType) # | |
| Generic (PgJSONEach valType f) Source # | |
Defined in Database.Beam.Postgres.PgSpecific Associated Types type Rep (PgJSONEach valType f) :: Type -> Type # Methods from :: PgJSONEach valType f -> Rep (PgJSONEach valType f) x # to :: Rep (PgJSONEach valType f) x -> PgJSONEach valType f # | |
| type Rep (PgJSONEach valType f) Source # | |
Defined in Database.Beam.Postgres.PgSpecific type Rep (PgJSONEach valType f) = D1 ('MetaData "PgJSONEach" "Database.Beam.Postgres.PgSpecific" "beam-postgres-0.5.1.0-7v9Z2BuUTTm5OBEuMV8Ty6" 'False) (C1 ('MetaCons "PgJSONEach" 'PrefixI 'True) (S1 ('MetaSel ('Just "pgJsonEachKey") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 (C f Text)) :*: S1 ('MetaSel ('Just "pgJsonEachValue") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 (C f valType)))) | |
Output row of pgJsonKeys
Instances
| Beamable PgJSONKey Source # | |
| Generic (PgJSONKey f) Source # | |
| type Rep (PgJSONKey f) Source # | |
Defined in Database.Beam.Postgres.PgSpecific | |
data PgJSONElement a f Source #
Output row of pgJsonArrayElements and pgJsonArrayElementsText
Constructors
| PgJSONElement | |
Fields
| |
Instances
(@>) :: QGenExpr ctxt Postgres s (PgJSONB a) -> QGenExpr ctxt Postgres s (PgJSONB b) -> QGenExpr ctxt Postgres s Bool Source #
Postgres @> and <@ operators for JSON. Return true if the
json object pointed to by the arrow is completely contained in the other. See
the Postgres documentation for more in formation on what this means.
(<@) :: QGenExpr ctxt Postgres s (PgJSONB a) -> QGenExpr ctxt Postgres s (PgJSONB b) -> QGenExpr ctxt Postgres s Bool Source #
Postgres @> and <@ operators for JSON. Return true if the
json object pointed to by the arrow is completely contained in the other. See
the Postgres documentation for more in formation on what this means.
(->#) :: IsPgJSON json => QGenExpr ctxt Postgres s (json a) -> QGenExpr ctxt Postgres s Int32 -> QGenExpr ctxt Postgres s (json b) Source #
Access a JSON array by index. Corresponds to the Postgres -> operator.
See (->$) for the corresponding operator for object access.
(->$) :: IsPgJSON json => QGenExpr ctxt Postgres s (json a) -> QGenExpr ctxt Postgres s Text -> QGenExpr ctxt Postgres s (json b) Source #
Acces a JSON object by key. Corresponds to the Postgres -> operator. See
(->#) for the corresponding operator for arrays.
(->>#) :: IsPgJSON json => QGenExpr ctxt Postgres s (json a) -> QGenExpr ctxt Postgres s Int32 -> QGenExpr ctxt Postgres s Text Source #
Access a JSON array by index, returning the embedded object as a string.
Corresponds to the Postgres ->> operator. See (->>$) for the
corresponding operator on objects.
(->>$) :: IsPgJSON json => QGenExpr ctxt Postgres s (json a) -> QGenExpr ctxt Postgres s Text -> QGenExpr ctxt Postgres s Text Source #
Access a JSON object by key, returning the embedded object as a string.
Corresponds to the Postgres ->> operator. See (->>#) for the
corresponding operator on arrays.
(#>) :: IsPgJSON json => QGenExpr ctxt Postgres s (json a) -> QGenExpr ctxt Postgres s (Vector Text) -> QGenExpr ctxt Postgres s (json b) Source #
Access a deeply nested JSON object. The first argument is the JSON object to look within, the second is the path of keys from the first argument to the target. Returns the result as a new json value. Note that the postgres function allows etiher string keys or integer indices, but this function only allows string keys. PRs to improve this functionality are welcome.
(#>>) :: IsPgJSON json => QGenExpr ctxt Postgres s (json a) -> QGenExpr ctxt Postgres s (Vector Text) -> QGenExpr ctxt Postgres s Text Source #
Like (#>) but returns the result as a string.
(?) :: QGenExpr ctxt Postgres s (PgJSONB a) -> QGenExpr ctxt Postgres s Text -> QGenExpr ctxt Postgres s Bool Source #
Postgres ? operator. Checks if the given string exists as top-level key
of the json object.
(?|) :: QGenExpr ctxt Postgres s (PgJSONB a) -> QGenExpr ctxt Postgres s (Vector Text) -> QGenExpr ctxt Postgres s Bool Source #
Postgres ?| and ?& operators. Check if any or all of the given strings
exist as top-level keys of the json object respectively.
(?&) :: QGenExpr ctxt Postgres s (PgJSONB a) -> QGenExpr ctxt Postgres s (Vector Text) -> QGenExpr ctxt Postgres s Bool Source #
Postgres ?| and ?& operators. Check if any or all of the given strings
exist as top-level keys of the json object respectively.
withoutKey :: QGenExpr ctxt Postgres s (PgJSONB a) -> QGenExpr ctxt Postgres s Text -> QGenExpr ctxt Postgres s (PgJSONB b) Source #
Postgres - operator on json objects. Returns the supplied json object
with the supplied key deleted. See withoutIdx for the corresponding
operator on arrays.
withoutIdx :: QGenExpr ctxt Postgres s (PgJSONB a) -> QGenExpr ctxt Postgres s Int32 -> QGenExpr ctxt Postgres s (PgJSONB b) Source #
Postgres - operator on json arrays. See withoutKey for the
corresponding operator on objects.
withoutKeys :: QGenExpr ctxt Postgres s (PgJSONB a) -> QGenExpr ctxt Postgres s (Vector Text) -> QGenExpr ctxt Postgres s (PgJSONB b) Source #
Postgres #- operator. Removes all the keys specificied from the JSON
object and returns the result.
pgJsonArrayLength :: IsPgJSON json => QGenExpr ctxt Postgres s (json a) -> QGenExpr ctxt Postgres s Int32 Source #
Postgres json_array_length function. The supplied json object should be
an array, but this isn't checked at compile-time.
pgArrayToJson :: QGenExpr ctxt Postgres s (Vector e) -> QGenExpr ctxt Postgres s (PgJSON a) Source #
Postgres array_to_json function.
pgJsonbUpdate :: QGenExpr ctxt Postgres s (PgJSONB a) -> QGenExpr ctxt Postgres s (Vector Text) -> QGenExpr ctxt Postgres s (PgJSONB b) -> QGenExpr ctxt Postgres s (PgJSONB a) Source #
The postgres jsonb_set function. pgJsonUpdate expects the value
specified by the path in the second argument to exist. If it does not, the
first argument is not modified. pgJsonbSet will create any intermediate
objects necessary. This corresponds to the create_missing argument of
jsonb_set being set to false or true respectively.
pgJsonbSet :: QGenExpr ctxt Postgres s (PgJSONB a) -> QGenExpr ctxt Postgres s (Vector Text) -> QGenExpr ctxt Postgres s (PgJSONB b) -> QGenExpr ctxt Postgres s (PgJSONB a) Source #
The postgres jsonb_set function. pgJsonUpdate expects the value
specified by the path in the second argument to exist. If it does not, the
first argument is not modified. pgJsonbSet will create any intermediate
objects necessary. This corresponds to the create_missing argument of
jsonb_set being set to false or true respectively.
pgJsonbPretty :: QGenExpr ctxt Postgres s (PgJSONB a) -> QGenExpr ctxt Postgres s Text Source #
Postgres jsonb_pretty function
MONEY data type
Postgres MONEY data type. A simple wrapper over ByteString, because
Postgres money format is locale-dependent, and we don't handle currency
symbol placement, digit grouping, or decimal separation.
The pgMoney function can be used to convert a number to PgMoney.
Constructors
| PgMoney | |
Fields | |
Instances
pgMoney :: Real a => a -> PgMoney Source #
Attempt to pack a floating point value as a PgMoney value, paying no
attention to the locale-dependent currency symbol, digit grouping, or decimal
point. This will use the . symbol as the decimal separator.
pgScaleMoney_ :: Num a => QGenExpr context Postgres s a -> QGenExpr context Postgres s PgMoney -> QGenExpr context Postgres s PgMoney Source #
Multiply a MONEY value by a numeric value. Corresponds to the Postgres
* operator.
pgDivideMoney_ :: Num a => QGenExpr context Postgres s PgMoney -> QGenExpr context Postgres s a -> QGenExpr context Postgres s PgMoney Source #
Divide a MONEY value by a numeric value. Corresponds to Postgres /
where the numerator has type MONEY and the denominator is a number. If you
would like to divide two MONEY values and have their units cancel out, use
pgDivideMoneys_.
pgDivideMoneys_ :: Num a => QGenExpr context Postgres s PgMoney -> QGenExpr context Postgres s PgMoney -> QGenExpr context Postgres s a Source #
Dividing two MONEY value results in a number. Corresponds to Postgres /
on two MONEY values. If you would like to divide MONEY by a scalar, use pgDivideMoney_
pgAddMoney_ :: QGenExpr context Postgres s PgMoney -> QGenExpr context Postgres s PgMoney -> QGenExpr context Postgres s PgMoney Source #
Postgres + and - operators on money.
pgSubtractMoney_ :: QGenExpr context Postgres s PgMoney -> QGenExpr context Postgres s PgMoney -> QGenExpr context Postgres s PgMoney Source #
Postgres + and - operators on money.
pgSumMoneyOver_ :: Maybe PgAggregationSetQuantifierSyntax -> QExpr Postgres s PgMoney -> QExpr Postgres s PgMoney Source #
The Postgres MONEY type can be summed or averaged in an aggregation.
These functions provide the quantified aggregations. See pgSumMoney_ and
pgAvgMoney_ for the unquantified versions.
pgAvgMoneyOver_ :: Maybe PgAggregationSetQuantifierSyntax -> QExpr Postgres s PgMoney -> QExpr Postgres s PgMoney Source #
The Postgres MONEY type can be summed or averaged in an aggregation.
These functions provide the quantified aggregations. See pgSumMoney_ and
pgAvgMoney_ for the unquantified versions.
pgSumMoney_ :: QExpr Postgres s PgMoney -> QExpr Postgres s PgMoney Source #
The Postgres MONEY type can be summed or averaged in an aggregation. To
provide an explicit quantification, see pgSumMoneyOver_ and
pgAvgMoneyOver_.
pgAvgMoney_ :: QExpr Postgres s PgMoney -> QExpr Postgres s PgMoney Source #
The Postgres MONEY type can be summed or averaged in an aggregation. To
provide an explicit quantification, see pgSumMoneyOver_ and
pgAvgMoneyOver_.
Geometry types (not PostGIS)
Instances
| Eq PgPoint Source # | |
| Ord PgPoint Source # | |
Defined in Database.Beam.Postgres.PgSpecific | |
| Show PgPoint Source # | |
| FromField PgPoint Source # | |
Defined in Database.Beam.Postgres.PgSpecific Methods | |
| HasSqlValueSyntax PgValueSyntax PgPoint Source # | |
Defined in Database.Beam.Postgres.PgSpecific Methods sqlValueSyntax :: PgPoint -> PgValueSyntax # | |
| FromBackendRow Postgres PgPoint Source # | |
Defined in Database.Beam.Postgres.PgSpecific Methods | |
| HasDefaultSqlDataType Postgres PgPoint Source # | |
Defined in Database.Beam.Postgres.PgSpecific Methods defaultSqlDataType :: Proxy PgPoint -> Proxy Postgres -> Bool -> BeamSqlBackendDataTypeSyntax Postgres # defaultSqlDataTypeConstraints :: Proxy PgPoint -> Proxy Postgres -> Bool -> [FieldCheck] # | |
Instances
| Eq PgLine Source # | |
| Ord PgLine Source # | |
| Show PgLine Source # | |
| HasSqlValueSyntax PgValueSyntax PgLine Source # | |
Defined in Database.Beam.Postgres.PgSpecific Methods sqlValueSyntax :: PgLine -> PgValueSyntax # | |
| HasDefaultSqlDataType Postgres PgLine Source # | |
Defined in Database.Beam.Postgres.PgSpecific Methods defaultSqlDataType :: Proxy PgLine -> Proxy Postgres -> Bool -> BeamSqlBackendDataTypeSyntax Postgres # defaultSqlDataTypeConstraints :: Proxy PgLine -> Proxy Postgres -> Bool -> [FieldCheck] # | |
data PgLineSegment Source #
Constructors
| PgLineSegment !PgPoint !PgPoint |
Instances
Instances
| Eq PgBox Source # | |
| Show PgBox Source # | |
| FromField PgBox Source # | |
Defined in Database.Beam.Postgres.PgSpecific Methods | |
| HasSqlValueSyntax PgValueSyntax PgBox Source # | |
Defined in Database.Beam.Postgres.PgSpecific Methods sqlValueSyntax :: PgBox -> PgValueSyntax # | |
| FromBackendRow Postgres PgBox Source # | |
Defined in Database.Beam.Postgres.PgSpecific Methods | |
| HasDefaultSqlDataType Postgres PgBox Source # | |
Defined in Database.Beam.Postgres.PgSpecific Methods defaultSqlDataType :: Proxy PgBox -> Proxy Postgres -> Bool -> BeamSqlBackendDataTypeSyntax Postgres # defaultSqlDataTypeConstraints :: Proxy PgBox -> Proxy Postgres -> Bool -> [FieldCheck] # | |
Constructors
| PgPathOpen (NonEmpty PgPoint) | |
| PgPathClosed (NonEmpty PgPoint) |
Instances
| Eq PgPolygon Source # | |
| Ord PgPolygon Source # | |
Defined in Database.Beam.Postgres.PgSpecific | |
| Show PgPolygon Source # | |
Regular expressions
The type of Postgres regular expressions. Only a
HasSqlValueSyntax instance is supplied, because you won't need to
be reading these back from the database.
If you're generating regexes dynamically, then use pgRegex_ to
convert a string expression into a regex one.
Instances
| Eq PgRegex Source # | |
| Ord PgRegex Source # | |
Defined in Database.Beam.Postgres.PgSpecific | |
| Show PgRegex Source # | |
| IsString PgRegex Source # | |
Defined in Database.Beam.Postgres.PgSpecific Methods fromString :: String -> PgRegex # | |
| HasSqlValueSyntax PgValueSyntax PgRegex Source # | |
Defined in Database.Beam.Postgres.PgSpecific Methods sqlValueSyntax :: PgRegex -> PgValueSyntax # | |
pgRegex_ :: BeamSqlBackendIsString Postgres text => QGenExpr ctxt Postgres s text -> QGenExpr ctxt Postgres s PgRegex Source #
Convert a string valued expression (which could be generated
dynamically) into a PgRegex-typed one.
(~.) :: BeamSqlBackendIsString Postgres text => QGenExpr ctxt Postgres s text -> QGenExpr ctxt Postgres s PgRegex -> QGenExpr ctxt Postgres s Bool Source #
Match regular expression, case-sensitive
(~*.) :: BeamSqlBackendIsString Postgres text => QGenExpr ctxt Postgres s text -> QGenExpr ctxt Postgres s PgRegex -> QGenExpr ctxt Postgres s Bool Source #
Match regular expression, case-insensitive
(!~.) :: BeamSqlBackendIsString Postgres text => QGenExpr ctxt Postgres s text -> QGenExpr ctxt Postgres s PgRegex -> QGenExpr ctxt Postgres s Bool Source #
Does not match regular expression, case-sensitive
(!~*.) :: BeamSqlBackendIsString Postgres text => QGenExpr ctxt Postgres s text -> QGenExpr ctxt Postgres s PgRegex -> QGenExpr ctxt Postgres s Bool Source #
Does not match regular expression, case-insensitive
pgRegexpReplace_ :: BeamSqlBackendIsString Postgres text => QGenExpr ctxt Postgres s text -> QGenExpr ctxt Postgres s PgRegex -> QGenExpr ctxt Postgres s text -> QGenExpr ctxt Postgres s Text -> QGenExpr ctxt Postgres s txt Source #
Postgres regexp_replace. Replaces all instances of the regex in
the first argument with the third argument. The fourth argument is
the postgres regex options to provide.
pgRegexpMatch_ :: BeamSqlBackendIsString Postgres text => QGenExpr ctxt Postgres s text -> QGenExpr ctxt Postgres s PgRegex -> QGenExpr ctxt Postgres s (Maybe (Vector text)) Source #
Postgres regexp_match. Matches the regular expression against
the string given and returns an array where each element
corresponds to a match in the string, or NULL if nothing was
found
pgRegexpSplitToTable :: BeamSqlBackendIsString Postgres text => QGenExpr ctxt Postgres s text -> QGenExpr ctxt Postgres s PgRegex -> Q Postgres db s (QExpr Postgres s Text) Source #
Postgres regexp_split_to_table. Splits the given string by the
given regex and return a result set that can be joined against.
pgRegexpSplitToArray :: BeamSqlBackendIsString Postgres text => QGenExpr ctxt Postgres s text -> QGenExpr ctxt Postgres s PgRegex -> QGenExpr ctxt Postgres s (Vector text) Source #
Postgres regexp_split_to_array. Splits the given string by the
given regex and returns the result as an array.
Set-valued functions
Postgres supports functions that returns sets. We can join directly against
these sets or arrays. beam-postgres supports this feature via the
pgUnnest and pgUnnestArray functions.
Any function that returns a set can be typed as an expression returning
PgSetOf. This polymorphic type takes one argument, which is a Beamable
type that represents the shape of the data in the rows. For example, the
json_each function returns a key and a value, so the corresponding
beam-postgres function (pgJsonEach) returns a value of type 'PgSetOf
(PgJSONEach Value)', which represents a set containing PgJSONEach
rows. PgJSONEach is a table with a column for keys (pgJsonEachKey) and
one for values (pgJsonEachValue).
Any PgSetOf value can be introduced into the Q monad using the pgUnnest
function.
Postgres arrays (represented by the Vector type) can also be joined
against using the pgUnnestArray function. This directly corresponds to the
SQL UNNEST keyword. Unlike sets, arrays have a sense of order. The
pgUnnestArrayWithOrdinality function allows you to join against the
elements of an array along with its index. This corresponds to the
UNNEST .. WITH ORDINALITY clause.
pgUnnest :: forall tbl db s. Beamable tbl => QExpr Postgres s (PgSetOf tbl) -> Q Postgres db s (QExprTable Postgres s tbl) Source #
Join the results of the given set-valued function to the query
pgUnnestArray :: QExpr Postgres s (Vector a) -> Q Postgres db s (QExpr Postgres s a) Source #
Introduce each element of the array as a row
pgUnnestArrayWithOrdinality :: QExpr Postgres s (Vector a) -> Q Postgres db s (QExpr Postgres s Int64, QExpr Postgres s a) Source #
Introduce each element of the array as a row, along with the element's index
ARRAY types
The functions and types in this section map Postgres ARRAY types to
Haskell. An array is serialized and deserialized to a Vector
object. This type most closely matches the semantics of Postgres ARRAYs. In
general, the names of functions in this section closely match names of the
native Postgres functions they map to. As with most beam expression
functions, names are suffixed with an underscore and CamelCased.
Note that Postgres supports arbitrary nesting of vectors. For example, two,
three, or higher dimensional arrays can be expressed, manipulated, and stored
in tables. Beam fully supports this use case. A two-dimensional postgres
array is represented as Vector (Vector a). Simply nest another Vector for
higher dimensions. Some functions that return data on arrays expect a
dimension number as a parameter. Since beam can check the dimension at
compile time, these functions expect a type-level Nat in the expression
DSL. The unsafe versions of these functions are also provided with the
Unsafe_ suffix. The safe versions are guaranteed not to fail at run-time
due to dimension mismatches, the unsafe ones may.
For more information on Postgres array support, refer to the postgres manual.
data PgArrayValueContext Source #
An expression context that determines which types of expressions can be put inside an array element. Any scalar, aggregate, or window expression can be placed within an array.
Instances
| PgIsArrayContext PgArrayValueContext Source # | |
Defined in Database.Beam.Postgres.PgSpecific Methods mkArraySyntax :: Proxy PgArrayValueContext -> PgSyntax -> PgSyntax | |
class PgIsArrayContext ctxt Source #
If you are extending beam-postgres and provide another expression context that can be represented in an array, provide an empty instance of this class.
Instances
| PgIsArrayContext QAggregateContext Source # | |
Defined in Database.Beam.Postgres.PgSpecific Methods mkArraySyntax :: Proxy QAggregateContext -> PgSyntax -> PgSyntax | |
| PgIsArrayContext QValueContext Source # | |
Defined in Database.Beam.Postgres.PgSpecific Methods mkArraySyntax :: Proxy QValueContext -> PgSyntax -> PgSyntax | |
| PgIsArrayContext QWindowingContext Source # | |
Defined in Database.Beam.Postgres.PgSpecific Methods mkArraySyntax :: Proxy QWindowingContext -> PgSyntax -> PgSyntax | |
| PgIsArrayContext PgArrayValueContext Source # | |
Defined in Database.Beam.Postgres.PgSpecific Methods mkArraySyntax :: Proxy PgArrayValueContext -> PgSyntax -> PgSyntax | |
Building ARRAYs
array_ :: forall context f s a. (PgIsArrayContext context, Foldable f) => f (QGenExpr context Postgres s a) -> QGenExpr context Postgres s (Vector a) Source #
Build a 1-dimensional postgres array from an arbitrary Foldable
containing expressions.
arrayOf_ :: Q Postgres db s (QExpr Postgres s a) -> QGenExpr context Postgres s (Vector a) Source #
Build a 1-dimensional postgres array from a subquery
(++.) :: QGenExpr ctxt Postgres s (Vector a) -> QGenExpr ctxt Postgres s (Vector a) -> QGenExpr ctxt Postgres s (Vector a) Source #
Postgres || operator. Concatenates two vectors and returns their result.
pgArrayAgg :: QExpr Postgres s a -> QAgg Postgres s (Vector a) Source #
An aggregate that adds each value to the resulting array. See pgArrayOver
if you want to specify a quantifier. Corresponds to the Postgres ARRAY_AGG
function.
pgArrayAggOver :: Maybe PgAggregationSetQuantifierSyntax -> QExpr Postgres s a -> QAgg Postgres s (Vector a) Source #
Postgres ARRAY_AGG with an explicit quantifier. Includes each row that
meets the quantification criteria in the result.
Array operators and functions
(!.) :: Integral ix => QGenExpr context Postgres s (Vector a) -> QGenExpr context Postgres s ix -> QGenExpr context Postgres s a Source #
arrayDims_ :: BeamSqlBackendIsString Postgres text => QGenExpr context Postgres s (Vector a) -> QGenExpr context Postgres s text Source #
Postgres array_dims() function. Returns a textual representation of the
dimensions of the array.
arrayUpper_ :: forall (dim :: Nat) context num v s. (KnownNat dim, WithinBounds dim (Vector v), Integral num) => QGenExpr context Postgres s (Vector v) -> QGenExpr context Postgres s num Source #
Return the upper or lower bound of the given array at the given dimension
(statically supplied as a type application on a Nat). Note
that beam will attempt to statically determine if the dimension is in range.
GHC errors will be thrown if this cannot be proved.
For example, to get the upper bound of the 2nd-dimension of an array:
arrayUpper_ @2 vectorValuedExpression
arrayLower_ :: forall (dim :: Nat) context num v s. (KnownNat dim, WithinBounds dim (Vector v), Integral num) => QGenExpr context Postgres s (Vector v) -> QGenExpr context Postgres s num Source #
Return the upper or lower bound of the given array at the given dimension
(statically supplied as a type application on a Nat). Note
that beam will attempt to statically determine if the dimension is in range.
GHC errors will be thrown if this cannot be proved.
For example, to get the upper bound of the 2nd-dimension of an array:
arrayUpper_ @2 vectorValuedExpression
arrayUpperUnsafe_ :: (Integral dim, Integral length) => QGenExpr context Postgres s (Vector v) -> QGenExpr context Postgres s dim -> QGenExpr context Postgres s (Maybe length) Source #
These functions can be used to find the lower and upper bounds of an array where the dimension number is not known until run-time. They are marked unsafe because they may cause query processing to fail at runtime, even if they typecheck successfully.
arrayLowerUnsafe_ :: (Integral dim, Integral length) => QGenExpr context Postgres s (Vector v) -> QGenExpr context Postgres s dim -> QGenExpr context Postgres s (Maybe length) Source #
These functions can be used to find the lower and upper bounds of an array where the dimension number is not known until run-time. They are marked unsafe because they may cause query processing to fail at runtime, even if they typecheck successfully.
arrayLength_ :: forall (dim :: Nat) ctxt num v s. (KnownNat dim, WithinBounds dim (Vector v), Integral num) => QGenExpr ctxt Postgres s (Vector v) -> QGenExpr ctxt Postgres s num Source #
Get the size of the array at the given (statically known) dimension,
provided as a type-level Nat. Like the arrayUpper_ and arrayLower_
functions,throws a compile-time error if the dimension is out of bounds.
arrayLengthUnsafe_ :: (Integral dim, Integral num) => QGenExpr ctxt Postgres s (Vector v) -> QGenExpr ctxt Postgres s dim -> QGenExpr ctxt Postgres s (Maybe num) Source #
Get the size of an array at a dimension not known until run-time. Marked unsafe as this may cause runtime errors even if it type checks.
isSupersetOf_ :: QGenExpr ctxt Postgres s (Vector a) -> QGenExpr ctxt Postgres s (Vector a) -> QGenExpr ctxt Postgres s Bool Source #
The Postgres @> operator. Returns true if every member of the second
array is present in the first.
isSubsetOf_ :: QGenExpr ctxt Postgres s (Vector a) -> QGenExpr ctxt Postgres s (Vector a) -> QGenExpr ctxt Postgres s Bool Source #
The Postgres <@ operator. Returns true if every member of the first
array is present in the second.
RANGE types
Postgres supports storing Range types in columns. There are serveral
predefined Range types and users may create their own. beam-postgres
fully supports these types, including user-defined range types. In general,
the names of functions in this section closely match names of the native
Postgres functions they map to. As with most beam expression functions,
names are suffixed with an underscore and CamelCased. Where ambiguous,
functions are prefixed with an r. Operators closely match their native
Postgres counterparts, except they are prefixed and/or suffixed with an -
to indicate the expression on that side is a Range. For example -<@- maps
to the native operator <@ when both arguments are Ranges, while <@- maps
to the same operator when the first argument is an element, not a range.
For more information on Postgres range support, refer to the postgres manual.
data PgRange (n :: *) a Source #
A range of a given Haskell type (represented by a) stored as a given Postgres Range Type
(represented by n).
A reasonable example might be Range PgInt8Range Int64.
This represents a range of Haskell Int64 values stored as a range of bigint in Postgres.
Constructors
| PgEmptyRange | |
| PgRange (PgRangeBound a) (PgRangeBound a) |
Instances
data PgRangeBound a Source #
Represents a single bound on a Range. A bound always has a type, but may not have a value (the absense of a value represents unbounded).
Constructors
| PgRangeBound PgBoundType (Maybe a) |
Instances
data PgBoundType Source #
Represents the types of bounds a range can have. A range can and often does have mis-matched bound types.
Instances
| Show PgBoundType Source # | |
Defined in Database.Beam.Postgres.PgSpecific Methods showsPrec :: Int -> PgBoundType -> ShowS # show :: PgBoundType -> String # showList :: [PgBoundType] -> ShowS # | |
| Generic PgBoundType Source # | |
Defined in Database.Beam.Postgres.PgSpecific Associated Types type Rep PgBoundType :: Type -> Type # | |
| Hashable PgBoundType Source # | |
Defined in Database.Beam.Postgres.PgSpecific | |
| type Rep PgBoundType Source # | |
Defined in Database.Beam.Postgres.PgSpecific | |
class PgIsRange n where Source #
A class representing Postgres Range types and how to refer to them when speaking to the database.
For custom Range types, create an uninhabited type, and make it an instance of this class.
Instances
| PgIsRange PgDateRange Source # | |
Defined in Database.Beam.Postgres.PgSpecific Methods | |
| PgIsRange PgTsTzRange Source # | |
Defined in Database.Beam.Postgres.PgSpecific Methods | |
| PgIsRange PgTsRange Source # | |
Defined in Database.Beam.Postgres.PgSpecific Methods | |
| PgIsRange PgNumRange Source # | |
Defined in Database.Beam.Postgres.PgSpecific Methods | |
| PgIsRange PgInt8Range Source # | |
Defined in Database.Beam.Postgres.PgSpecific Methods | |
| PgIsRange PgInt4Range Source # | |
Defined in Database.Beam.Postgres.PgSpecific Methods | |
data PgInt4Range Source #
Instances
| PgIsRange PgInt4Range Source # | |
Defined in Database.Beam.Postgres.PgSpecific Methods | |
data PgInt8Range Source #
Instances
| PgIsRange PgInt8Range Source # | |
Defined in Database.Beam.Postgres.PgSpecific Methods | |
data PgNumRange Source #
Instances
| PgIsRange PgNumRange Source # | |
Defined in Database.Beam.Postgres.PgSpecific Methods | |
Instances
| PgIsRange PgTsRange Source # | |
Defined in Database.Beam.Postgres.PgSpecific Methods | |
data PgTsTzRange Source #
Instances
| PgIsRange PgTsTzRange Source # | |
Defined in Database.Beam.Postgres.PgSpecific Methods | |
data PgDateRange Source #
Instances
| PgIsRange PgDateRange Source # | |
Defined in Database.Beam.Postgres.PgSpecific Methods | |
Building ranges from expressions
Building PgRangeBounds
inclusive :: a -> PgRangeBound a Source #
exclusive :: a -> PgRangeBound a Source #
unbounded :: PgRangeBound a Source #
Range operators and functions
(-@>-) :: QGenExpr context Postgres s (PgRange n a) -> QGenExpr context Postgres s (PgRange n a) -> QGenExpr context Postgres s Bool Source #
(-@>) :: QGenExpr context Postgres s (PgRange n a) -> QGenExpr context Postgres s a -> QGenExpr context Postgres s Bool Source #
(-<@-) :: QGenExpr context Postgres s (PgRange n a) -> QGenExpr context Postgres s (PgRange n a) -> QGenExpr context Postgres s Bool Source #
(<@-) :: QGenExpr context Postgres s a -> QGenExpr context Postgres s (PgRange n a) -> QGenExpr context Postgres s Bool Source #
(-&&-) :: QGenExpr context Postgres s (PgRange n a) -> QGenExpr context Postgres s (PgRange n a) -> QGenExpr context Postgres s Bool Source #
(-<<-) :: QGenExpr context Postgres s (PgRange n a) -> QGenExpr context Postgres s (PgRange n a) -> QGenExpr context Postgres s Bool Source #
(->>-) :: QGenExpr context Postgres s (PgRange n a) -> QGenExpr context Postgres s (PgRange n a) -> QGenExpr context Postgres s Bool Source #
(-&<-) :: QGenExpr context Postgres s (PgRange n a) -> QGenExpr context Postgres s (PgRange n a) -> QGenExpr context Postgres s Bool Source #
(-&>-) :: QGenExpr context Postgres s (PgRange n a) -> QGenExpr context Postgres s (PgRange n a) -> QGenExpr context Postgres s Bool Source #
(--|--) :: QGenExpr context Postgres s (PgRange n a) -> QGenExpr context Postgres s (PgRange n a) -> QGenExpr context Postgres s Bool Source #
(-+-) :: QGenExpr context Postgres s (PgRange n a) -> QGenExpr context Postgres s (PgRange n a) -> QGenExpr context Postgres s (PgRange n a) Source #
(-*-) :: QGenExpr context Postgres s (PgRange n a) -> QGenExpr context Postgres s (PgRange n a) -> QGenExpr context Postgres s (PgRange n a) Source #
(-.-) :: QGenExpr context Postgres s (PgRange n a) -> QGenExpr context Postgres s (PgRange n a) -> QGenExpr context Postgres s (PgRange n a) Source #
The postgres range operator - .
rLower_ :: QGenExpr context Postgres s (PgRange n a) -> QGenExpr context Postgres s (Maybe a) Source #
rUpper_ :: QGenExpr context Postgres s (PgRange n a) -> QGenExpr context Postgres s (Maybe a) Source #
rangeMerge_ :: QGenExpr context Postgres s (PgRange n a) -> QGenExpr context Postgres s (PgRange n a) -> QGenExpr context Postgres s (PgRange n a) Source #
Postgres functions and aggregates
pgBoolOr :: QExpr Postgres s a -> QAgg Postgres s (Maybe Bool) Source #
Postgres bool_or aggregate. Returns true if any of the rows are true.
pgBoolAnd :: QExpr Postgres s a -> QAgg Postgres s (Maybe Bool) Source #
Postgres bool_and aggregate. Returns false unless every row is true.
pgStringAgg :: BeamSqlBackendIsString Postgres str => QExpr Postgres s str -> QExpr Postgres s str -> QAgg Postgres s (Maybe str) Source #
Joins the string value in each row of the first argument, using the second
argument as a delimiter. See pgStringAggOver if you want to provide
explicit quantification.
pgStringAggOver :: BeamSqlBackendIsString Postgres str => Maybe PgAggregationSetQuantifierSyntax -> QExpr Postgres s str -> QExpr Postgres s str -> QAgg Postgres s (Maybe str) Source #
The Postgres string_agg function, with an explicit quantifier. Joins the
values of the second argument using the delimiter given by the third.
pgNubBy_ :: (Projectible Postgres key, Projectible Postgres r) => (r -> key) -> Q Postgres db s r -> Q Postgres db s r Source #
Modify a query to only return rows where the supplied key function returns
a unique value. This corresponds to the Postgres DISTINCT ON support.
ilike_ :: BeamSqlBackendIsString Postgres text => QExpr Postgres s text -> QExpr Postgres s text -> QExpr Postgres s Bool Source #
Postgres ILIKE operator. A case-insensitive version of like_.
runBeamPostgres :: Connection -> Pg a -> IO a Source #
runBeamPostgresDebug :: (String -> IO ()) -> Connection -> Pg a -> IO a Source #
Postgres extension support
data PgExtensionEntity extension Source #
Represents an extension in a database.
For example, to include the Database.Beam.Postgres.PgCrypto extension in a database,
import Database.Beam.Postgres.PgCrypto
data MyDatabase entity
= MyDatabase
{ _table1 :: entity (TableEntity Table1)
, _cryptoExtension :: entity (PgExtensionEntity PgCrypto)
}
migratableDbSettings :: CheckedDatabaseSettings Postgres MyDatabase
migratableDbSettings = defaultMigratableDbSettings
dbSettings :: DatabaseSettings Postgres MyDatabase
dbSettings = unCheckDatabase migratableDbSettings
Note that our database now only works in the Postgres backend.
Extensions are implemented as records of functions and values that expose
extension functionality. For example, the pgcrypto extension (implemented
by PgCrypto) provides cryptographic functions. Thus, PgCrypto is a record
of functions over QGenExpr which wrap the underlying postgres
functionality.
You get access to these functions by retrieving them from the entity in the database.
For example, to use the pgcrypto extension in the database above:
let PgCrypto { pgCryptoDigestText = digestText
, pgCryptoCrypt = crypt } = getPgExtension (_cryptoExtension dbSettings)
in fmap_ (tbl -> (tbl, crypt (_field1 tbl) (_salt tbl))) (all_ (table1 dbSettings))
To implement your own extension, create a record type, and implement the
IsPgExtension type class.
Instances
class IsPgExtension extension where Source #
Type class implemented by any Postgresql extension
Methods
pgExtensionName :: Proxy extension -> Text Source #
Return the name of this extension. This should be the string that is
passed to CREATE EXTENSION. For example, PgCrypto returns "pgcrypto".
pgExtensionBuild :: extension Source #
Return a value of this extension type. This should fill in all fields in
the record. For example, PgCrypto builds a record where each function
wraps the underlying Postgres one.
Instances
pgCreateExtension :: forall extension db. IsPgExtension extension => Migration Postgres (CheckedDatabaseEntity Postgres db (PgExtensionEntity extension)) Source #
Migration representing the Postgres CREATE EXTENSION command. Because
the extension name is statically known by the extension type and
IsPgExtension type class, this simply produces the checked extension
entity.
If you need to use the extension in subsequent migration steps, use
getPgExtension and unCheck to get access to the underlying
DatabaseEntity.
pgDropExtension :: forall extension. CheckedDatabaseEntityDescriptor Postgres (PgExtensionEntity extension) -> Migration Postgres () Source #
Migration representing the Postgres DROP EXTENSION. After this
executes, you should expect any further uses of the extension to fail.
Unfortunately, without linear types, we cannot check this.
getPgExtension :: DatabaseEntity Postgres db (PgExtensionEntity extension) -> extension Source #
Get the extension record from a database entity. See the documentation for
PgExtensionEntity.
Utilities for defining custom instances
fromPgIntegral :: forall a. (FromField a, Integral a, Typeable a) => FromBackendRowM Postgres a Source #
Deserialize integral fields, possibly downcasting from a larger integral type, but only if we won't lose data
fromPgScientificOrIntegral :: (Bounded a, Integral a) => FromBackendRowM Postgres a Source #
Deserialize integral fields, possibly downcasting from a larger numeric type
via Scientific if we won't lose data, and then falling back to any integral
type via Integer
Debug support
class PgDebugStmt statement Source #
Type class for Sql* types that can be turned into Postgres
syntax, for use in the following debugging functions
These include
Minimal complete definition
pgStmtSyntax
Instances
pgTraceStmtIO :: PgDebugStmt statement => Connection -> statement -> IO () Source #
pgTraceStmtIO' :: PgDebugStmt statement => Connection -> statement -> IO ByteString Source #
pgTraceStmt :: PgDebugStmt statement => statement -> Pg () Source #
postgresql-simple re-exports
data ResultError #
Exception thrown if conversion from a SQL value to a Haskell value fails.
Constructors
| Incompatible | The SQL and Haskell types are not compatible. |
Fields
| |
| UnexpectedNull | A SQL |
Fields
| |
| ConversionFailed | The SQL value could not be parsed, or could not be represented as a valid Haskell value, or an unexpected low-level error occurred (e.g. mismatch between metadata and actual data in a row). |
Fields
| |
Instances
| Eq ResultError | |
Defined in Database.PostgreSQL.Simple.FromField | |
| Show ResultError | |
Defined in Database.PostgreSQL.Simple.FromField Methods showsPrec :: Int -> ResultError -> ShowS # show :: ResultError -> String # showList :: [ResultError] -> ShowS # | |
| Exception ResultError | |
Defined in Database.PostgreSQL.Simple.FromField Methods toException :: ResultError -> SomeException # fromException :: SomeException -> Maybe ResultError # displayException :: ResultError -> String # | |
Constructors
| SqlError | |
Fields | |
Instances
| Eq SqlError | |
| Show SqlError | |
| Exception SqlError | |
Defined in Database.PostgreSQL.Simple.Internal Methods toException :: SqlError -> SomeException # fromException :: SomeException -> Maybe SqlError # displayException :: SqlError -> String # | |
data Connection #
Instances
| Eq Connection | |
Defined in Database.PostgreSQL.Simple.Internal | |
data ConnectInfo #
Constructors
| ConnectInfo | |
Fields
| |
Instances
defaultConnectInfo :: ConnectInfo #
Default information for setting up a connection.
Defaults are as follows:
- Server on
localhost - Port on
5432 - User
postgres - No password
- Database
postgres
Use as in the following example:
connect defaultConnectInfo { connectHost = "db.example.com" }connectPostgreSQL :: ByteString -> IO Connection #
Attempt to make a connection based on a libpq connection string. See https://www.postgresql.org/docs/9.5/static/libpq-connect.html#LIBPQ-CONNSTRING for more information. Also note that environment variables also affect parameters not provided, parameters provided as the empty string, and a few other things; see https://www.postgresql.org/docs/9.5/static/libpq-envars.html for details. Here is an example with some of the most commonly used parameters:
host='db.somedomain.com' port=5432 ...
This attempts to connect to db.somedomain.com:5432. Omitting the port
will normally default to 5432.
On systems that provide unix domain sockets, omitting the host parameter
will cause libpq to attempt to connect via unix domain sockets.
The default filesystem path to the socket is constructed from the
port number and the DEFAULT_PGSOCKET_DIR constant defined in the
pg_config_manual.h header file. Connecting via unix sockets tends
to use the peer authentication method, which is very secure and
does not require a password.
On Windows and other systems without unix domain sockets, omitting
the host will default to localhost.
... dbname='postgres' user='postgres' password='secret \' \\ pw'
This attempts to connect to a database named postgres with
user postgres and password secret ' \ pw. Backslash
characters will have to be double-quoted in literal Haskell strings,
of course. Omitting dbname and user will both default to the
system username that the client process is running as.
Omitting password will default to an appropriate password found
in the pgpass file, or no password at all if a matching line is
not found. The path of the pgpass file may be specified by setting
the PGPASSFILE environment variable. See
https://www.postgresql.org/docs/9.5/static/libpq-pgpass.html for
more information regarding this file.
As all parameters are optional and the defaults are sensible, the empty connection string can be useful for development and exploratory use, assuming your system is set up appropriately.
On Unix, such a setup would typically consist of a local postgresql server listening on port 5432, as well as a system user, database user, and database sharing a common name, with permissions granted to the user on the database.
On Windows, in addition you will either need pg_hba.conf
to specify the use of the trust authentication method for
the connection, which may not be appropriate for multiuser
or production machines, or you will need to use a pgpass file
with the password or md5 authentication methods.
See https://www.postgresql.org/docs/9.5/static/client-authentication.html for more information regarding the authentication process.
SSL/TLS will typically "just work" if your postgresql server supports or
requires it. However, note that libpq is trivially vulnerable to a MITM
attack without setting additional SSL connection parameters. In
particular, sslmode needs to be set to require, verify-ca, or
verify-full in order to perform certificate validation. When sslmode
is require, then you will also need to specify a sslrootcert file,
otherwise no validation of the server's identity will be performed.
Client authentication via certificates is also possible via the
sslcert and sslkey parameters. See
https://www.postgresql.org/docs/9.5/static/libpq-ssl.html
for detailed information regarding libpq and SSL.
connect :: ConnectInfo -> IO Connection #
Connect with the given username to the given database. Will throw an exception if it cannot connect.
close :: Connection -> IO () #