psycopg/psycopg2
1
1
Fork 0
mirror of https://github.com/psycopg/psycopg2.git synced 2024-12-01 13:13:45 +03:00
Code Issues Packages Projects Releases Wiki Activity

Added documentation for the with statement

Browse Source
This commit is contained in:
Daniele Varrazzo 2012-12-03 03:18:51 +00:00
parent cc605032f5
commit c2f284cd3b
3 changed files with 37 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
doc/src/connection.rst
View File

@ -74,6 +74,10 @@ The ``connection`` class
automatically open, commands have immediate effect. See automatically open, commands have immediate effect. See
:ref:`transactions-control` for details. :ref:`transactions-control` for details.
.. versionchanged:: 2.5 if the connection is used in a ``with``
statement, the method is automatically called if no exception is
raised in the ``with`` block.
.. index:: .. index::
pair: Transaction; Rollback pair: Transaction; Rollback
@ -84,6 +88,10 @@ The ``connection`` class
connection without committing the changes first will cause an implicit connection without committing the changes first will cause an implicit
rollback to be performed. rollback to be performed.
.. versionchanged:: 2.5 if the connection is used in a ``with``
statement, the method is automatically called if an exception is
raised in the ``with`` block.
.. method:: close() .. method:: close()

5
doc/src/cursor.rst
View File

@ -84,6 +84,11 @@ The ``cursor`` class
`~psycopg2.InterfaceError` will be raised if any operation is `~psycopg2.InterfaceError` will be raised if any operation is
attempted with the cursor. attempted with the cursor.
.. versionchanged:: 2.5 if the cursor is used in a ``with`` statement,
the method is automatically called at the end of the ``with``
block.
.. attribute:: closed .. attribute:: closed
Read-only boolean attribute: specifies if the cursor is closed Read-only boolean attribute: specifies if the cursor is closed

24
doc/src/usage.rst
View File

@ -548,6 +548,30 @@ change the isolation level. See the `~connection.set_session()` method for all
the details. the details.
.. index::
single: with statement
``with`` statement
^^^^^^^^^^^^^^^^^^
Starting from version 2.5, psycopg2's connections and cursors are *context
managers* and can be used with the ``with`` statement::
with psycopg2.connect(DSN) as conn:
with conn.cursor() as curs:
curs.execute(SQL)
When a connection exits the ``with`` block, if no exception has been raised by
the block, the transaction is committed. In case of exception the transaction
is rolled back. In no case the connection is closed: a connection can be used
in more than a ``with`` statement and each ``with`` block is effectively
wrapped in a transaction.
When a cursor exits the ``with`` block it is closed, releasing any resource
eventually associated with it. The state of the transaction is not affected.
.. index:: .. index::
pair: Server side; Cursor pair: Server side; Cursor
pair: Named; Cursor pair: Named; Cursor