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877 lines
31 KiB
877 lines
31 KiB
# dialects/postgresql/psycopg2.py
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# Copyright (C) 2005-2024 the SQLAlchemy authors and contributors
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# <see AUTHORS file>
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#
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# This module is part of SQLAlchemy and is released under
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# the MIT License: https://www.opensource.org/licenses/mit-license.php
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# mypy: ignore-errors
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r"""
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.. dialect:: postgresql+psycopg2
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:name: psycopg2
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:dbapi: psycopg2
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:connectstring: postgresql+psycopg2://user:password@host:port/dbname[?key=value&key=value...]
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:url: https://pypi.org/project/psycopg2/
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.. _psycopg2_toplevel:
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psycopg2 Connect Arguments
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--------------------------
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Keyword arguments that are specific to the SQLAlchemy psycopg2 dialect
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may be passed to :func:`_sa.create_engine()`, and include the following:
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* ``isolation_level``: This option, available for all PostgreSQL dialects,
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includes the ``AUTOCOMMIT`` isolation level when using the psycopg2
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dialect. This option sets the **default** isolation level for the
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connection that is set immediately upon connection to the database before
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the connection is pooled. This option is generally superseded by the more
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modern :paramref:`_engine.Connection.execution_options.isolation_level`
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execution option, detailed at :ref:`dbapi_autocommit`.
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.. seealso::
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:ref:`psycopg2_isolation_level`
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:ref:`dbapi_autocommit`
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* ``client_encoding``: sets the client encoding in a libpq-agnostic way,
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using psycopg2's ``set_client_encoding()`` method.
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.. seealso::
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:ref:`psycopg2_unicode`
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* ``executemany_mode``, ``executemany_batch_page_size``,
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``executemany_values_page_size``: Allows use of psycopg2
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extensions for optimizing "executemany"-style queries. See the referenced
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section below for details.
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.. seealso::
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:ref:`psycopg2_executemany_mode`
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.. tip::
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The above keyword arguments are **dialect** keyword arguments, meaning
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that they are passed as explicit keyword arguments to :func:`_sa.create_engine()`::
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engine = create_engine(
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"postgresql+psycopg2://scott:tiger@localhost/test",
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isolation_level="SERIALIZABLE",
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)
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These should not be confused with **DBAPI** connect arguments, which
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are passed as part of the :paramref:`_sa.create_engine.connect_args`
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dictionary and/or are passed in the URL query string, as detailed in
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the section :ref:`custom_dbapi_args`.
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.. _psycopg2_ssl:
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SSL Connections
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---------------
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The psycopg2 module has a connection argument named ``sslmode`` for
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controlling its behavior regarding secure (SSL) connections. The default is
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``sslmode=prefer``; it will attempt an SSL connection and if that fails it
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will fall back to an unencrypted connection. ``sslmode=require`` may be used
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to ensure that only secure connections are established. Consult the
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psycopg2 / libpq documentation for further options that are available.
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Note that ``sslmode`` is specific to psycopg2 so it is included in the
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connection URI::
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engine = sa.create_engine(
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"postgresql+psycopg2://scott:tiger@192.168.0.199:5432/test?sslmode=require"
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)
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Unix Domain Connections
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------------------------
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psycopg2 supports connecting via Unix domain connections. When the ``host``
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portion of the URL is omitted, SQLAlchemy passes ``None`` to psycopg2,
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which specifies Unix-domain communication rather than TCP/IP communication::
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create_engine("postgresql+psycopg2://user:password@/dbname")
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By default, the socket file used is to connect to a Unix-domain socket
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in ``/tmp``, or whatever socket directory was specified when PostgreSQL
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was built. This value can be overridden by passing a pathname to psycopg2,
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using ``host`` as an additional keyword argument::
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create_engine("postgresql+psycopg2://user:password@/dbname?host=/var/lib/postgresql")
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.. warning:: The format accepted here allows for a hostname in the main URL
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in addition to the "host" query string argument. **When using this URL
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format, the initial host is silently ignored**. That is, this URL::
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engine = create_engine("postgresql+psycopg2://user:password@myhost1/dbname?host=myhost2")
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Above, the hostname ``myhost1`` is **silently ignored and discarded.** The
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host which is connected is the ``myhost2`` host.
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This is to maintain some degree of compatibility with PostgreSQL's own URL
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format which has been tested to behave the same way and for which tools like
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PifPaf hardcode two hostnames.
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.. seealso::
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`PQconnectdbParams \
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<https://www.postgresql.org/docs/current/static/libpq-connect.html#LIBPQ-PQCONNECTDBPARAMS>`_
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.. _psycopg2_multi_host:
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Specifying multiple fallback hosts
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-----------------------------------
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psycopg2 supports multiple connection points in the connection string.
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When the ``host`` parameter is used multiple times in the query section of
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the URL, SQLAlchemy will create a single string of the host and port
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information provided to make the connections. Tokens may consist of
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``host::port`` or just ``host``; in the latter case, the default port
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is selected by libpq. In the example below, three host connections
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are specified, for ``HostA::PortA``, ``HostB`` connecting to the default port,
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and ``HostC::PortC``::
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create_engine(
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"postgresql+psycopg2://user:password@/dbname?host=HostA:PortA&host=HostB&host=HostC:PortC"
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)
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As an alternative, libpq query string format also may be used; this specifies
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``host`` and ``port`` as single query string arguments with comma-separated
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lists - the default port can be chosen by indicating an empty value
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in the comma separated list::
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create_engine(
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"postgresql+psycopg2://user:password@/dbname?host=HostA,HostB,HostC&port=PortA,,PortC"
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)
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With either URL style, connections to each host is attempted based on a
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configurable strategy, which may be configured using the libpq
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``target_session_attrs`` parameter. Per libpq this defaults to ``any``
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which indicates a connection to each host is then attempted until a connection is successful.
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Other strategies include ``primary``, ``prefer-standby``, etc. The complete
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list is documented by PostgreSQL at
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`libpq connection strings <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNSTRING>`_.
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For example, to indicate two hosts using the ``primary`` strategy::
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create_engine(
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"postgresql+psycopg2://user:password@/dbname?host=HostA:PortA&host=HostB&host=HostC:PortC&target_session_attrs=primary"
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)
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.. versionchanged:: 1.4.40 Port specification in psycopg2 multiple host format
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is repaired, previously ports were not correctly interpreted in this context.
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libpq comma-separated format is also now supported.
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.. versionadded:: 1.3.20 Support for multiple hosts in PostgreSQL connection
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string.
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.. seealso::
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`libpq connection strings <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNSTRING>`_ - please refer
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to this section in the libpq documentation for complete background on multiple host support.
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Empty DSN Connections / Environment Variable Connections
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---------------------------------------------------------
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The psycopg2 DBAPI can connect to PostgreSQL by passing an empty DSN to the
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libpq client library, which by default indicates to connect to a localhost
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PostgreSQL database that is open for "trust" connections. This behavior can be
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further tailored using a particular set of environment variables which are
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prefixed with ``PG_...``, which are consumed by ``libpq`` to take the place of
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any or all elements of the connection string.
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For this form, the URL can be passed without any elements other than the
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initial scheme::
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engine = create_engine('postgresql+psycopg2://')
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In the above form, a blank "dsn" string is passed to the ``psycopg2.connect()``
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function which in turn represents an empty DSN passed to libpq.
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.. versionadded:: 1.3.2 support for parameter-less connections with psycopg2.
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.. seealso::
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`Environment Variables\
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<https://www.postgresql.org/docs/current/libpq-envars.html>`_ -
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PostgreSQL documentation on how to use ``PG_...``
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environment variables for connections.
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.. _psycopg2_execution_options:
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Per-Statement/Connection Execution Options
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-------------------------------------------
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The following DBAPI-specific options are respected when used with
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:meth:`_engine.Connection.execution_options`,
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:meth:`.Executable.execution_options`,
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:meth:`_query.Query.execution_options`,
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in addition to those not specific to DBAPIs:
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* ``isolation_level`` - Set the transaction isolation level for the lifespan
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of a :class:`_engine.Connection` (can only be set on a connection,
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not a statement
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or query). See :ref:`psycopg2_isolation_level`.
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* ``stream_results`` - Enable or disable usage of psycopg2 server side
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cursors - this feature makes use of "named" cursors in combination with
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special result handling methods so that result rows are not fully buffered.
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Defaults to False, meaning cursors are buffered by default.
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* ``max_row_buffer`` - when using ``stream_results``, an integer value that
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specifies the maximum number of rows to buffer at a time. This is
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interpreted by the :class:`.BufferedRowCursorResult`, and if omitted the
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buffer will grow to ultimately store 1000 rows at a time.
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.. versionchanged:: 1.4 The ``max_row_buffer`` size can now be greater than
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1000, and the buffer will grow to that size.
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.. _psycopg2_batch_mode:
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.. _psycopg2_executemany_mode:
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Psycopg2 Fast Execution Helpers
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-------------------------------
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Modern versions of psycopg2 include a feature known as
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`Fast Execution Helpers \
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<https://initd.org/psycopg/docs/extras.html#fast-execution-helpers>`_, which
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have been shown in benchmarking to improve psycopg2's executemany()
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performance, primarily with INSERT statements, by at least
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an order of magnitude.
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SQLAlchemy implements a native form of the "insert many values"
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handler that will rewrite a single-row INSERT statement to accommodate for
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many values at once within an extended VALUES clause; this handler is
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equivalent to psycopg2's ``execute_values()`` handler; an overview of this
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feature and its configuration are at :ref:`engine_insertmanyvalues`.
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.. versionadded:: 2.0 Replaced psycopg2's ``execute_values()`` fast execution
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helper with a native SQLAlchemy mechanism known as
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:ref:`insertmanyvalues <engine_insertmanyvalues>`.
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The psycopg2 dialect retains the ability to use the psycopg2-specific
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``execute_batch()`` feature, although it is not expected that this is a widely
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used feature. The use of this extension may be enabled using the
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``executemany_mode`` flag which may be passed to :func:`_sa.create_engine`::
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engine = create_engine(
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"postgresql+psycopg2://scott:tiger@host/dbname",
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executemany_mode='values_plus_batch')
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Possible options for ``executemany_mode`` include:
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* ``values_only`` - this is the default value. SQLAlchemy's native
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:ref:`insertmanyvalues <engine_insertmanyvalues>` handler is used for qualifying
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INSERT statements, assuming
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:paramref:`_sa.create_engine.use_insertmanyvalues` is left at
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its default value of ``True``. This handler rewrites simple
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INSERT statements to include multiple VALUES clauses so that many
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parameter sets can be inserted with one statement.
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* ``'values_plus_batch'``- SQLAlchemy's native
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:ref:`insertmanyvalues <engine_insertmanyvalues>` handler is used for qualifying
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INSERT statements, assuming
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:paramref:`_sa.create_engine.use_insertmanyvalues` is left at its default
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value of ``True``. Then, psycopg2's ``execute_batch()`` handler is used for
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qualifying UPDATE and DELETE statements when executed with multiple parameter
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sets. When using this mode, the :attr:`_engine.CursorResult.rowcount`
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attribute will not contain a value for executemany-style executions against
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UPDATE and DELETE statements.
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.. versionchanged:: 2.0 Removed the ``'batch'`` and ``'None'`` options
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from psycopg2 ``executemany_mode``. Control over batching for INSERT
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statements is now configured via the
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:paramref:`_sa.create_engine.use_insertmanyvalues` engine-level parameter.
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The term "qualifying statements" refers to the statement being executed
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being a Core :func:`_expression.insert`, :func:`_expression.update`
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or :func:`_expression.delete` construct, and **not** a plain textual SQL
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string or one constructed using :func:`_expression.text`. It also may **not** be
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a special "extension" statement such as an "ON CONFLICT" "upsert" statement.
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When using the ORM, all insert/update/delete statements used by the ORM flush process
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are qualifying.
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The "page size" for the psycopg2 "batch" strategy can be affected
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by using the ``executemany_batch_page_size`` parameter, which defaults to
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100.
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For the "insertmanyvalues" feature, the page size can be controlled using the
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:paramref:`_sa.create_engine.insertmanyvalues_page_size` parameter,
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which defaults to 1000. An example of modifying both parameters
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is below::
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engine = create_engine(
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"postgresql+psycopg2://scott:tiger@host/dbname",
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executemany_mode='values_plus_batch',
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insertmanyvalues_page_size=5000, executemany_batch_page_size=500)
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.. seealso::
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:ref:`engine_insertmanyvalues` - background on "insertmanyvalues"
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:ref:`tutorial_multiple_parameters` - General information on using the
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:class:`_engine.Connection`
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object to execute statements in such a way as to make
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use of the DBAPI ``.executemany()`` method.
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.. _psycopg2_unicode:
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Unicode with Psycopg2
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----------------------
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The psycopg2 DBAPI driver supports Unicode data transparently.
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The client character encoding can be controlled for the psycopg2 dialect
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in the following ways:
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* For PostgreSQL 9.1 and above, the ``client_encoding`` parameter may be
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passed in the database URL; this parameter is consumed by the underlying
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``libpq`` PostgreSQL client library::
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engine = create_engine("postgresql+psycopg2://user:pass@host/dbname?client_encoding=utf8")
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Alternatively, the above ``client_encoding`` value may be passed using
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:paramref:`_sa.create_engine.connect_args` for programmatic establishment with
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``libpq``::
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engine = create_engine(
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"postgresql+psycopg2://user:pass@host/dbname",
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connect_args={'client_encoding': 'utf8'}
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)
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* For all PostgreSQL versions, psycopg2 supports a client-side encoding
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value that will be passed to database connections when they are first
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established. The SQLAlchemy psycopg2 dialect supports this using the
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``client_encoding`` parameter passed to :func:`_sa.create_engine`::
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engine = create_engine(
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"postgresql+psycopg2://user:pass@host/dbname",
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client_encoding="utf8"
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)
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.. tip:: The above ``client_encoding`` parameter admittedly is very similar
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in appearance to usage of the parameter within the
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:paramref:`_sa.create_engine.connect_args` dictionary; the difference
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above is that the parameter is consumed by psycopg2 and is
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passed to the database connection using ``SET client_encoding TO
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'utf8'``; in the previously mentioned style, the parameter is instead
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passed through psycopg2 and consumed by the ``libpq`` library.
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* A common way to set up client encoding with PostgreSQL databases is to
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ensure it is configured within the server-side postgresql.conf file;
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this is the recommended way to set encoding for a server that is
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consistently of one encoding in all databases::
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# postgresql.conf file
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# client_encoding = sql_ascii # actually, defaults to database
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# encoding
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client_encoding = utf8
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Transactions
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------------
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The psycopg2 dialect fully supports SAVEPOINT and two-phase commit operations.
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.. _psycopg2_isolation_level:
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Psycopg2 Transaction Isolation Level
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-------------------------------------
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As discussed in :ref:`postgresql_isolation_level`,
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all PostgreSQL dialects support setting of transaction isolation level
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both via the ``isolation_level`` parameter passed to :func:`_sa.create_engine`
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,
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as well as the ``isolation_level`` argument used by
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:meth:`_engine.Connection.execution_options`. When using the psycopg2 dialect
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, these
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options make use of psycopg2's ``set_isolation_level()`` connection method,
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rather than emitting a PostgreSQL directive; this is because psycopg2's
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API-level setting is always emitted at the start of each transaction in any
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case.
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The psycopg2 dialect supports these constants for isolation level:
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* ``READ COMMITTED``
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* ``READ UNCOMMITTED``
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* ``REPEATABLE READ``
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* ``SERIALIZABLE``
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* ``AUTOCOMMIT``
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.. seealso::
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:ref:`postgresql_isolation_level`
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:ref:`pg8000_isolation_level`
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NOTICE logging
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---------------
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The psycopg2 dialect will log PostgreSQL NOTICE messages
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via the ``sqlalchemy.dialects.postgresql`` logger. When this logger
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is set to the ``logging.INFO`` level, notice messages will be logged::
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import logging
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logging.getLogger('sqlalchemy.dialects.postgresql').setLevel(logging.INFO)
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Above, it is assumed that logging is configured externally. If this is not
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the case, configuration such as ``logging.basicConfig()`` must be utilized::
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import logging
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logging.basicConfig() # log messages to stdout
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logging.getLogger('sqlalchemy.dialects.postgresql').setLevel(logging.INFO)
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.. seealso::
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`Logging HOWTO <https://docs.python.org/3/howto/logging.html>`_ - on the python.org website
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.. _psycopg2_hstore:
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HSTORE type
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------------
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The ``psycopg2`` DBAPI includes an extension to natively handle marshalling of
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the HSTORE type. The SQLAlchemy psycopg2 dialect will enable this extension
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by default when psycopg2 version 2.4 or greater is used, and
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it is detected that the target database has the HSTORE type set up for use.
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In other words, when the dialect makes the first
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connection, a sequence like the following is performed:
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1. Request the available HSTORE oids using
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``psycopg2.extras.HstoreAdapter.get_oids()``.
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If this function returns a list of HSTORE identifiers, we then determine
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that the ``HSTORE`` extension is present.
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This function is **skipped** if the version of psycopg2 installed is
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less than version 2.4.
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2. If the ``use_native_hstore`` flag is at its default of ``True``, and
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we've detected that ``HSTORE`` oids are available, the
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``psycopg2.extensions.register_hstore()`` extension is invoked for all
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connections.
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The ``register_hstore()`` extension has the effect of **all Python
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dictionaries being accepted as parameters regardless of the type of target
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column in SQL**. The dictionaries are converted by this extension into a
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textual HSTORE expression. If this behavior is not desired, disable the
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use of the hstore extension by setting ``use_native_hstore`` to ``False`` as
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follows::
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engine = create_engine("postgresql+psycopg2://scott:tiger@localhost/test",
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use_native_hstore=False)
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The ``HSTORE`` type is **still supported** when the
|
|
``psycopg2.extensions.register_hstore()`` extension is not used. It merely
|
|
means that the coercion between Python dictionaries and the HSTORE
|
|
string format, on both the parameter side and the result side, will take
|
|
place within SQLAlchemy's own marshalling logic, and not that of ``psycopg2``
|
|
which may be more performant.
|
|
|
|
""" # noqa
|
|
from __future__ import annotations
|
|
|
|
import collections.abc as collections_abc
|
|
import logging
|
|
import re
|
|
from typing import cast
|
|
|
|
from . import ranges
|
|
from ._psycopg_common import _PGDialect_common_psycopg
|
|
from ._psycopg_common import _PGExecutionContext_common_psycopg
|
|
from .base import PGIdentifierPreparer
|
|
from .json import JSON
|
|
from .json import JSONB
|
|
from ... import types as sqltypes
|
|
from ... import util
|
|
from ...util import FastIntFlag
|
|
from ...util import parse_user_argument_for_enum
|
|
|
|
logger = logging.getLogger("sqlalchemy.dialects.postgresql")
|
|
|
|
|
|
class _PGJSON(JSON):
|
|
def result_processor(self, dialect, coltype):
|
|
return None
|
|
|
|
|
|
class _PGJSONB(JSONB):
|
|
def result_processor(self, dialect, coltype):
|
|
return None
|
|
|
|
|
|
class _Psycopg2Range(ranges.AbstractSingleRangeImpl):
|
|
_psycopg2_range_cls = "none"
|
|
|
|
def bind_processor(self, dialect):
|
|
psycopg2_Range = getattr(
|
|
cast(PGDialect_psycopg2, dialect)._psycopg2_extras,
|
|
self._psycopg2_range_cls,
|
|
)
|
|
|
|
def to_range(value):
|
|
if isinstance(value, ranges.Range):
|
|
value = psycopg2_Range(
|
|
value.lower, value.upper, value.bounds, value.empty
|
|
)
|
|
return value
|
|
|
|
return to_range
|
|
|
|
def result_processor(self, dialect, coltype):
|
|
def to_range(value):
|
|
if value is not None:
|
|
value = ranges.Range(
|
|
value._lower,
|
|
value._upper,
|
|
bounds=value._bounds if value._bounds else "[)",
|
|
empty=not value._bounds,
|
|
)
|
|
return value
|
|
|
|
return to_range
|
|
|
|
|
|
class _Psycopg2NumericRange(_Psycopg2Range):
|
|
_psycopg2_range_cls = "NumericRange"
|
|
|
|
|
|
class _Psycopg2DateRange(_Psycopg2Range):
|
|
_psycopg2_range_cls = "DateRange"
|
|
|
|
|
|
class _Psycopg2DateTimeRange(_Psycopg2Range):
|
|
_psycopg2_range_cls = "DateTimeRange"
|
|
|
|
|
|
class _Psycopg2DateTimeTZRange(_Psycopg2Range):
|
|
_psycopg2_range_cls = "DateTimeTZRange"
|
|
|
|
|
|
class PGExecutionContext_psycopg2(_PGExecutionContext_common_psycopg):
|
|
_psycopg2_fetched_rows = None
|
|
|
|
def post_exec(self):
|
|
self._log_notices(self.cursor)
|
|
|
|
def _log_notices(self, cursor):
|
|
# check also that notices is an iterable, after it's already
|
|
# established that we will be iterating through it. This is to get
|
|
# around test suites such as SQLAlchemy's using a Mock object for
|
|
# cursor
|
|
if not cursor.connection.notices or not isinstance(
|
|
cursor.connection.notices, collections_abc.Iterable
|
|
):
|
|
return
|
|
|
|
for notice in cursor.connection.notices:
|
|
# NOTICE messages have a
|
|
# newline character at the end
|
|
logger.info(notice.rstrip())
|
|
|
|
cursor.connection.notices[:] = []
|
|
|
|
|
|
class PGIdentifierPreparer_psycopg2(PGIdentifierPreparer):
|
|
pass
|
|
|
|
|
|
class ExecutemanyMode(FastIntFlag):
|
|
EXECUTEMANY_VALUES = 0
|
|
EXECUTEMANY_VALUES_PLUS_BATCH = 1
|
|
|
|
|
|
(
|
|
EXECUTEMANY_VALUES,
|
|
EXECUTEMANY_VALUES_PLUS_BATCH,
|
|
) = ExecutemanyMode.__members__.values()
|
|
|
|
|
|
class PGDialect_psycopg2(_PGDialect_common_psycopg):
|
|
driver = "psycopg2"
|
|
|
|
supports_statement_cache = True
|
|
supports_server_side_cursors = True
|
|
|
|
default_paramstyle = "pyformat"
|
|
# set to true based on psycopg2 version
|
|
supports_sane_multi_rowcount = False
|
|
execution_ctx_cls = PGExecutionContext_psycopg2
|
|
preparer = PGIdentifierPreparer_psycopg2
|
|
psycopg2_version = (0, 0)
|
|
use_insertmanyvalues_wo_returning = True
|
|
|
|
returns_native_bytes = False
|
|
|
|
_has_native_hstore = True
|
|
|
|
colspecs = util.update_copy(
|
|
_PGDialect_common_psycopg.colspecs,
|
|
{
|
|
JSON: _PGJSON,
|
|
sqltypes.JSON: _PGJSON,
|
|
JSONB: _PGJSONB,
|
|
ranges.INT4RANGE: _Psycopg2NumericRange,
|
|
ranges.INT8RANGE: _Psycopg2NumericRange,
|
|
ranges.NUMRANGE: _Psycopg2NumericRange,
|
|
ranges.DATERANGE: _Psycopg2DateRange,
|
|
ranges.TSRANGE: _Psycopg2DateTimeRange,
|
|
ranges.TSTZRANGE: _Psycopg2DateTimeTZRange,
|
|
},
|
|
)
|
|
|
|
def __init__(
|
|
self,
|
|
executemany_mode="values_only",
|
|
executemany_batch_page_size=100,
|
|
**kwargs,
|
|
):
|
|
_PGDialect_common_psycopg.__init__(self, **kwargs)
|
|
|
|
if self._native_inet_types:
|
|
raise NotImplementedError(
|
|
"The psycopg2 dialect does not implement "
|
|
"ipaddress type handling; native_inet_types cannot be set "
|
|
"to ``True`` when using this dialect."
|
|
)
|
|
|
|
# Parse executemany_mode argument, allowing it to be only one of the
|
|
# symbol names
|
|
self.executemany_mode = parse_user_argument_for_enum(
|
|
executemany_mode,
|
|
{
|
|
EXECUTEMANY_VALUES: ["values_only"],
|
|
EXECUTEMANY_VALUES_PLUS_BATCH: ["values_plus_batch"],
|
|
},
|
|
"executemany_mode",
|
|
)
|
|
|
|
self.executemany_batch_page_size = executemany_batch_page_size
|
|
|
|
if self.dbapi and hasattr(self.dbapi, "__version__"):
|
|
m = re.match(r"(\d+)\.(\d+)(?:\.(\d+))?", self.dbapi.__version__)
|
|
if m:
|
|
self.psycopg2_version = tuple(
|
|
int(x) for x in m.group(1, 2, 3) if x is not None
|
|
)
|
|
|
|
if self.psycopg2_version < (2, 7):
|
|
raise ImportError(
|
|
"psycopg2 version 2.7 or higher is required."
|
|
)
|
|
|
|
def initialize(self, connection):
|
|
super().initialize(connection)
|
|
self._has_native_hstore = (
|
|
self.use_native_hstore
|
|
and self._hstore_oids(connection.connection.dbapi_connection)
|
|
is not None
|
|
)
|
|
|
|
self.supports_sane_multi_rowcount = (
|
|
self.executemany_mode is not EXECUTEMANY_VALUES_PLUS_BATCH
|
|
)
|
|
|
|
@classmethod
|
|
def import_dbapi(cls):
|
|
import psycopg2
|
|
|
|
return psycopg2
|
|
|
|
@util.memoized_property
|
|
def _psycopg2_extensions(cls):
|
|
from psycopg2 import extensions
|
|
|
|
return extensions
|
|
|
|
@util.memoized_property
|
|
def _psycopg2_extras(cls):
|
|
from psycopg2 import extras
|
|
|
|
return extras
|
|
|
|
@util.memoized_property
|
|
def _isolation_lookup(self):
|
|
extensions = self._psycopg2_extensions
|
|
return {
|
|
"AUTOCOMMIT": extensions.ISOLATION_LEVEL_AUTOCOMMIT,
|
|
"READ COMMITTED": extensions.ISOLATION_LEVEL_READ_COMMITTED,
|
|
"READ UNCOMMITTED": extensions.ISOLATION_LEVEL_READ_UNCOMMITTED,
|
|
"REPEATABLE READ": extensions.ISOLATION_LEVEL_REPEATABLE_READ,
|
|
"SERIALIZABLE": extensions.ISOLATION_LEVEL_SERIALIZABLE,
|
|
}
|
|
|
|
def set_isolation_level(self, dbapi_connection, level):
|
|
dbapi_connection.set_isolation_level(self._isolation_lookup[level])
|
|
|
|
def set_readonly(self, connection, value):
|
|
connection.readonly = value
|
|
|
|
def get_readonly(self, connection):
|
|
return connection.readonly
|
|
|
|
def set_deferrable(self, connection, value):
|
|
connection.deferrable = value
|
|
|
|
def get_deferrable(self, connection):
|
|
return connection.deferrable
|
|
|
|
def on_connect(self):
|
|
extras = self._psycopg2_extras
|
|
|
|
fns = []
|
|
if self.client_encoding is not None:
|
|
|
|
def on_connect(dbapi_conn):
|
|
dbapi_conn.set_client_encoding(self.client_encoding)
|
|
|
|
fns.append(on_connect)
|
|
|
|
if self.dbapi:
|
|
|
|
def on_connect(dbapi_conn):
|
|
extras.register_uuid(None, dbapi_conn)
|
|
|
|
fns.append(on_connect)
|
|
|
|
if self.dbapi and self.use_native_hstore:
|
|
|
|
def on_connect(dbapi_conn):
|
|
hstore_oids = self._hstore_oids(dbapi_conn)
|
|
if hstore_oids is not None:
|
|
oid, array_oid = hstore_oids
|
|
kw = {"oid": oid}
|
|
kw["array_oid"] = array_oid
|
|
extras.register_hstore(dbapi_conn, **kw)
|
|
|
|
fns.append(on_connect)
|
|
|
|
if self.dbapi and self._json_deserializer:
|
|
|
|
def on_connect(dbapi_conn):
|
|
extras.register_default_json(
|
|
dbapi_conn, loads=self._json_deserializer
|
|
)
|
|
extras.register_default_jsonb(
|
|
dbapi_conn, loads=self._json_deserializer
|
|
)
|
|
|
|
fns.append(on_connect)
|
|
|
|
if fns:
|
|
|
|
def on_connect(dbapi_conn):
|
|
for fn in fns:
|
|
fn(dbapi_conn)
|
|
|
|
return on_connect
|
|
else:
|
|
return None
|
|
|
|
def do_executemany(self, cursor, statement, parameters, context=None):
|
|
if self.executemany_mode is EXECUTEMANY_VALUES_PLUS_BATCH:
|
|
if self.executemany_batch_page_size:
|
|
kwargs = {"page_size": self.executemany_batch_page_size}
|
|
else:
|
|
kwargs = {}
|
|
self._psycopg2_extras.execute_batch(
|
|
cursor, statement, parameters, **kwargs
|
|
)
|
|
else:
|
|
cursor.executemany(statement, parameters)
|
|
|
|
def do_begin_twophase(self, connection, xid):
|
|
connection.connection.tpc_begin(xid)
|
|
|
|
def do_prepare_twophase(self, connection, xid):
|
|
connection.connection.tpc_prepare()
|
|
|
|
def _do_twophase(self, dbapi_conn, operation, xid, recover=False):
|
|
if recover:
|
|
if dbapi_conn.status != self._psycopg2_extensions.STATUS_READY:
|
|
dbapi_conn.rollback()
|
|
operation(xid)
|
|
else:
|
|
operation()
|
|
|
|
def do_rollback_twophase(
|
|
self, connection, xid, is_prepared=True, recover=False
|
|
):
|
|
dbapi_conn = connection.connection.dbapi_connection
|
|
self._do_twophase(
|
|
dbapi_conn, dbapi_conn.tpc_rollback, xid, recover=recover
|
|
)
|
|
|
|
def do_commit_twophase(
|
|
self, connection, xid, is_prepared=True, recover=False
|
|
):
|
|
dbapi_conn = connection.connection.dbapi_connection
|
|
self._do_twophase(
|
|
dbapi_conn, dbapi_conn.tpc_commit, xid, recover=recover
|
|
)
|
|
|
|
@util.memoized_instancemethod
|
|
def _hstore_oids(self, dbapi_connection):
|
|
extras = self._psycopg2_extras
|
|
oids = extras.HstoreAdapter.get_oids(dbapi_connection)
|
|
if oids is not None and oids[0]:
|
|
return oids[0:2]
|
|
else:
|
|
return None
|
|
|
|
def is_disconnect(self, e, connection, cursor):
|
|
if isinstance(e, self.dbapi.Error):
|
|
# check the "closed" flag. this might not be
|
|
# present on old psycopg2 versions. Also,
|
|
# this flag doesn't actually help in a lot of disconnect
|
|
# situations, so don't rely on it.
|
|
if getattr(connection, "closed", False):
|
|
return True
|
|
|
|
# checks based on strings. in the case that .closed
|
|
# didn't cut it, fall back onto these.
|
|
str_e = str(e).partition("\n")[0]
|
|
for msg in [
|
|
# these error messages from libpq: interfaces/libpq/fe-misc.c
|
|
# and interfaces/libpq/fe-secure.c.
|
|
"terminating connection",
|
|
"closed the connection",
|
|
"connection not open",
|
|
"could not receive data from server",
|
|
"could not send data to server",
|
|
# psycopg2 client errors, psycopg2/connection.h,
|
|
# psycopg2/cursor.h
|
|
"connection already closed",
|
|
"cursor already closed",
|
|
# not sure where this path is originally from, it may
|
|
# be obsolete. It really says "losed", not "closed".
|
|
"losed the connection unexpectedly",
|
|
# these can occur in newer SSL
|
|
"connection has been closed unexpectedly",
|
|
"SSL error: decryption failed or bad record mac",
|
|
"SSL SYSCALL error: Bad file descriptor",
|
|
"SSL SYSCALL error: EOF detected",
|
|
"SSL SYSCALL error: Operation timed out",
|
|
"SSL SYSCALL error: Bad address",
|
|
]:
|
|
idx = str_e.find(msg)
|
|
if idx >= 0 and '"' not in str_e[:idx]:
|
|
return True
|
|
return False
|
|
|
|
|
|
dialect = PGDialect_psycopg2
|