| Copyright | (c) 2013 Leon P Smith |
|---|---|
| License | BSD3 |
| Maintainer | Leon P Smith <leon@melding-monads.com> |
| Stability | experimental |
| Safe Haskell | None |
| Language | Haskell98 |
Database.PostgreSQL.Simple.Copy
Description
mid-level support for COPY IN and COPY OUT. See https://www.postgresql.org/docs/9.5/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
- 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 CopyOutResult Source #
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 Int64 Source #
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.