def __next__(self):
try:
return next(self._row_iter)
except AttributeError:
if self._context is None:
raise ProgrammingError("A query hasn't been issued.")
else:
raise
except StopIteration as e:
if self._context is None:
raise ProgrammingError("A query hasn't been issued.")
elif len(self._context.columns) == 0:
raise ProgrammingError("no result set")
else:
raise e
def tpc_rollback(self, xid=None):
"""When called with no arguments, .tpc_rollback() rolls back a TPC
transaction. It may be called before or after .tpc_prepare().
When called with a transaction ID xid, it rolls back the given
transaction. If an invalid transaction ID is provided, a
ProgrammingError is raised. This form should be called outside of a
transaction, and is intended for use in recovery.
On return, the TPC transaction is ended.
This function is part of the `DBAPI 2.0 specification
<http://www.python.org/dev/peps/pep-0249/>`_.
"""
if xid is None:
xid = self._xid
if xid is None:
raise ProgrammingError(
"Cannot tpc_rollback() without a TPC prepared transaction!")
try:
previous_autocommit_mode = self.autocommit
self.autocommit = True
if xid in self.tpc_recover():
# a two-phase rollback
self.execute_unnamed("ROLLBACK PREPARED '%s';" % (xid[1], ))
else:
# a single-phase rollback
self.rollback()
finally:
self.autocommit = previous_autocommit_mode
self._xid = None
def tpc_commit(self, xid=None):
"""When called with no arguments, .tpc_commit() commits a TPC
transaction previously prepared with .tpc_prepare().
If .tpc_commit() is called prior to .tpc_prepare(), a single phase
commit is performed. A transaction manager may choose to do this if
only a single resource is participating in the global transaction.
When called with a transaction ID xid, the database commits the given
transaction. If an invalid transaction ID is provided, a
ProgrammingError will be raised. This form should be called outside of
a transaction, and is intended for use in recovery.
On return, the TPC transaction is ended.
This function is part of the `DBAPI 2.0 specification
<http://www.python.org/dev/peps/pep-0249/>`_.
"""
if xid is None:
xid = self._xid
if xid is None:
raise ProgrammingError("Cannot tpc_commit() without a TPC transaction!")
try:
previous_autocommit_mode = self.autocommit
self.autocommit = True
if xid in self.tpc_recover():
self.execute_unnamed("COMMIT PREPARED '%s';" % (xid[1],))
else:
# a single-phase commit
self.commit()
finally:
self.autocommit = previous_autocommit_mode
self._xid = None
def fetchone(self):
"""Fetch the next row of a query result set.
This method is part of the `DBAPI 2.0 specification
<http://www.python.org/dev/peps/pep-0249/>`_.
:returns:
A row as a sequence of field values, or ``None`` if no more rows
are available.
"""
try:
return next(self)
except StopIteration:
return None
except TypeError:
raise ProgrammingError("attempting to use unexecuted cursor")
except AttributeError:
raise ProgrammingError("attempting to use unexecuted cursor")
def fetchall(self):
"""Fetches all remaining rows of a query result.
This method is part of the `DBAPI 2.0 specification
<http://www.python.org/dev/peps/pep-0249/>`_.
:returns:
A sequence, each entry of which is a sequence of field values
making up a row.
"""
try:
return tuple(self)
except TypeError:
raise ProgrammingError("attempting to use unexecuted cursor")
def __init__(self, *args, **kwargs):
try:
super().__init__(*args, **kwargs)
except DatabaseError as e:
msg = e.args[0]
if isinstance(msg, dict):
response_code = msg["C"]
if response_code == "28000":
cls = InterfaceError
elif response_code == "23505":
cls = IntegrityError
else:
cls = ProgrammingError
raise cls(msg)
else:
raise ProgrammingError(msg)
self._run_cursor = Cursor(self, paramstyle="named")
def fetchmany(self, num=None):
"""Fetches the next set of rows of a query result.
This method is part of the `DBAPI 2.0 specification
<http://www.python.org/dev/peps/pep-0249/>`_.
:param size:
The number of rows to fetch when called. If not provided, the
:attr:`arraysize` attribute value is used instead.
:returns:
A sequence, each entry of which is a sequence of field values
making up a row. If no more rows are available, an empty sequence
will be returned.
"""
try:
return tuple(islice(self, self.arraysize if num is None else num))
except TypeError:
raise ProgrammingError("attempting to use unexecuted cursor")
def execute(self, operation, args=(), stream=None):
"""Executes a database operation. Parameters may be provided as a
sequence, or as a mapping, depending upon the value of
:data:`pg8000.paramstyle`.
This method is part of the `DBAPI 2.0 specification
<http://www.python.org/dev/peps/pep-0249/>`_.
:param operation:
The SQL statement to execute.
:param args:
If :data:`paramstyle` is ``qmark``, ``numeric``, or ``format``,
this argument should be an array of parameters to bind into the
statement. If :data:`paramstyle` is ``named``, the argument should
be a dict mapping of parameters. If the :data:`paramstyle` is
``pyformat``, the argument value may be either an array or a
mapping.
:param stream: This is a pg8000 extension for use with the PostgreSQL
`COPY
<http://www.postgresql.org/docs/current/static/sql-copy.html>`_
command. For a COPY FROM the parameter must be a readable file-like
object, and for COPY TO it must be writable.
.. versionadded:: 1.9.11
"""
try:
if not self._c.in_transaction and not self._c.autocommit:
self._c.execute_unnamed("begin transaction")
statement, vals = convert_paramstyle(self.paramstyle, operation,
args)
self._context = self._c.execute_unnamed(
statement,
vals=vals,
input_oids=self._input_oids,
stream=stream)
rows = [] if self._context.rows is None else self._context.rows
self._row_iter = iter(rows)
self._input_oids = None
except AttributeError as e:
if self._c is None:
raise InterfaceError("Cursor closed")
elif self._c._sock is None:
raise InterfaceError("connection is closed")
else:
raise e
except DatabaseError as e:
msg = e.args[0]
if isinstance(msg, dict):
response_code = msg["C"]
if response_code == "28000":
cls = InterfaceError
elif response_code == "23505":
cls = IntegrityError
else:
cls = ProgrammingError
raise cls(msg)
else:
raise ProgrammingError(msg)
self.input_types = []
return self
