| Safe Haskell | None |
|---|---|
| Language | Haskell2010 |
Opaleye.Internal.RunQuery
Synopsis
- data FromField pgType haskellType = QueryRunnerColumn (Unpackspec (Column pgType) ()) (FieldParser haskellType)
- type QueryRunnerColumn = FromField
- data FromFields columns haskells = QueryRunner (Unpackspec columns ()) (columns -> RowParser haskells) (columns -> Int)
- type QueryRunner = FromFields
- fieldQueryRunnerColumn :: FromField haskell => FromField pgType haskell
- fromPGSFromField :: FromField haskell => FromField pgType haskell
- fieldParserQueryRunnerColumn :: FieldParser haskell -> FromField pgType haskell
- fromPGSFieldParser :: FieldParser haskell -> FromField pgType haskell
- queryRunner :: FromField a b -> FromFields (Column a) b
- queryRunnerColumnNullable :: FromField a b -> FromField (Nullable a) (Maybe b)
- unsafeFromFieldRaw :: FromField a (Field, Maybe ByteString)
- class DefaultFromField sqlType haskellType where
- queryRunnerColumnDefault :: FromField sqlType haskellType
- defaultFromField :: FromField sqlType haskellType
- type QueryRunnerColumnDefault = DefaultFromField
- arrayColumn :: Column (SqlArray a) -> Column a
- fromFieldArray :: Typeable h => FromField f h -> FromField (SqlArray f) [h]
- fromFieldRange :: Typeable b => FromField a b -> FromField (PGRange a) (PGRange b)
- jsonFieldParser :: FieldParser String
- jsonbFieldParser :: FieldParser String
- jsonFieldTextParser :: FieldParser Text
- jsonbFieldTextParser :: FieldParser Text
- jsonFieldLazyTextParser :: FieldParser Text
- jsonbFieldLazyTextParser :: FieldParser Text
- jsonFieldByteParser :: FieldParser ByteString
- jsonbFieldByteParser :: FieldParser ByteString
- jsonFieldLazyByteParser :: FieldParser ByteString
- jsonbFieldLazyByteParser :: FieldParser ByteString
- jsonFieldTypeParser :: ByteString -> FieldParser String
- jsonFieldTypeTextParser :: ByteString -> FieldParser Text
- jsonFieldTypeLazyTextParser :: ByteString -> FieldParser Text
- jsonFieldTypeByteParser :: ByteString -> FieldParser ByteString
- jsonFieldTypeLazyByteParser :: ByteString -> FieldParser ByteString
- prepareRowParser :: FromFields columns haskells -> columns -> RowParser haskells
- data Cursor haskells
- = EmptyCursor
- | Cursor (RowParser haskells) Cursor
- prepareQuery :: FromFields fields haskells -> Select fields -> (Maybe Query, RowParser haskells)
Documentation
data FromField pgType haskellType Source #
A FromField sqlType haskellType
encodes how to turn
a value of Postgres type sqlType into a value of Haskell type
haskellType. For example a value of type FromField
SqlText String encodes how to turn a SqlText result from the
database into a Haskell String.
"FromField sqlType haskellType" corresponds to
postgresql-simple's "FieldParser haskellType".
Constructors
| QueryRunnerColumn (Unpackspec (Column pgType) ()) (FieldParser haskellType) |
Instances
type QueryRunnerColumn = FromField Source #
data FromFields columns haskells Source #
A FromFields
specifies how to convert Postgres values (fields)
into Haskell values (haskells). Most likely you will never need
to create on of these or handle one directly. It will be provided
for you by the Default FromFields instance.
"FromFields fields haskells" corresponds to
postgresql-simple's "RowParser haskells". "Default
FromFields columns haskells" corresponds to
postgresql-simple's "FromRow haskells".
Constructors
| QueryRunner (Unpackspec columns ()) (columns -> RowParser haskells) (columns -> Int) |
Instances
type QueryRunner = FromFields Source #
fieldQueryRunnerColumn :: FromField haskell => FromField pgType haskell Source #
fromPGSFromField :: FromField haskell => FromField pgType haskell Source #
fieldParserQueryRunnerColumn :: FieldParser haskell -> FromField pgType haskell Source #
fromPGSFieldParser :: FieldParser haskell -> FromField pgType haskell Source #
queryRunner :: FromField a b -> FromFields (Column a) b Source #
unsafeFromFieldRaw :: FromField a (Field, Maybe ByteString) Source #
class DefaultFromField sqlType haskellType where Source #
A DefaultFromField sqlType haskellType represents
the default way to turn a sqlType result from the database into a
Haskell value of type haskellType.
"DefaultFromField sqlType haskellType" corresponds
to postgresql-simple's "FromField haskellType".
Creating an instance of DefaultFromField for your own types is
necessary for retrieving those types from the database.
You should use one of the three methods below for writing a
DefaultFromField instance.
- If you already have a postgresql-simple
FromFieldinstance for yourhaskellType, usefromPGSFromField. (This is how most of the built-in instances are defined.) - If you don't have a postgresql-simple
FromFieldinstance, but you do have an OpaleyeFromFieldvalue for the type it wraps useunsafeFromFieldif possible. See the documentation forunsafeFromFieldfor an example. - If you have a more complicated case, but not a
FromFieldinstance, write aFieldParserfor your type and usefromPGSFieldParser. You can also add aFromFieldinstance using this.
Minimal complete definition
Methods
queryRunnerColumnDefault :: FromField sqlType haskellType Source #
Deprecated: Use defaultFromField instead. It will be removed in 0.8
defaultFromField :: FromField sqlType haskellType Source #
Instances
prepareRowParser :: FromFields columns haskells -> columns -> RowParser haskells Source #
Cursor within a transaction.
Constructors
| EmptyCursor | |
| Cursor (RowParser haskells) Cursor |
prepareQuery :: FromFields fields haskells -> Select fields -> (Maybe Query, RowParser haskells) Source #