| Stability | experimental |
|---|---|
| Maintainer | Leon P Smith <leon@melding-monads.com> |
| Safe Haskell | None |
Database.PostgreSQL.Simple.Copy
Description
mid-level support for COPY IN and COPY OUT. See http://www.postgresql.org/docs/9.2/static/sql-copy.html for more information.
To use this binding, first call copy with an appropriate query as documented in the link above. Then, in the case of a COPY TO STDOUT query, call getCopyData repeatedly until it returns CopyOutDone. In the case of a COPY FROM STDIN query, call putCopyData repeatedly and then finish by calling either putCopyEnd to proceed or putCopyError to abort.
You cannot issue another query on the same connection while a copy is ongoing; this will result in an exception. It is harmless to concurrently call getNotification on a connection while it is in a CopyIn or CopyOut state, however be aware that current versions of the PostgreSQL backend will not deliver notifications to a client while a transaction is ongoing.
- copy :: ToRow params => Connection -> Query -> params -> IO ()
- copy_ :: Connection -> Query -> IO ()
- data CopyOutResult
- = CopyOutRow !ByteString
- | CopyOutDone !Int64
- getCopyData :: Connection -> IO CopyOutResult
- putCopyData :: Connection -> ByteString -> IO ()
- putCopyEnd :: Connection -> IO Int64
- putCopyError :: Connection -> ByteString -> IO ()
Documentation
copy :: ToRow params => Connection -> Query -> params -> IO ()Source
Issue a COPY FROM STDIN or COPY TO STDOUT query. In the former case, the connection's state will change to CopyIn; in the latter, CopyOut. The connection must be in the ready state in order to call this function. Performs parameter subsitution.
copy_ :: Connection -> Query -> IO ()Source
Issue a COPY FROM STDIN or COPY TO STDOUT query. In the former case, the connection's state will change to CopyIn; in the latter, CopyOut. The connection must be in the ready state in order to call this function. Does not perform parameter subsitution.
data CopyOutResult Source
Constructors
| CopyOutRow !ByteString | Data representing either exactly one row of the result, or header or footer data depending on format. |
| CopyOutDone !Int64 | No more rows, and a count of the number of rows returned. |
Instances
getCopyData :: Connection -> IO CopyOutResultSource
Retrieve some data from a COPY TO STDOUT query. A connection must be in the CopyOut state in order to call this function. If this returns a CopyOutRow, the connection remains in the CopyOut state, if it returns CopyOutDone, then the connection has reverted to the ready state.
putCopyData :: Connection -> ByteString -> IO ()Source
Feed some data to a COPY FROM STDIN query. Note that the data does not need to represent a single row, or even an integral number of rows. The net result of putCopyData conn a >> putCopyData conn b is the same as putCopyData conn c whenever c == BS.append a b.
A connection must be in the CopyIn state in order to call this function, otherwise a SqlError exception will result. The connection remains in the CopyIn state after this function is called.
putCopyEnd :: Connection -> IO Int64Source
Completes a COPY FROM STDIN query. Returns the number of rows processed.
A connection must be in the CopyIn state in order to call this function, otherwise a SqlError exception will result. The connection's state changes back to ready after this function is called.
putCopyError :: Connection -> ByteString -> IO ()Source
Aborts a COPY FROM STDIN query. The string parameter is simply an arbitrary error message that may show up in the PostgreSQL server's log.
A connection must be in the CopyIn state in order to call this function, otherwise a SqlError exception will result. The connection's state changes back to ready after this function is called.