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authorErlend Egeberg Aasland <erlend.aasland@protonmail.com>2022-07-26 06:29:18 (GMT)
committerGitHub <noreply@github.com>2022-07-26 06:29:18 (GMT)
commit5012bedc7ca7d78b5a42bf60eef55bac263f4060 (patch)
tree0fdc4d11c0101ef041466303e05a68cbd1d14221 /Doc/library/sqlite3.rst
parent68c555a50a2b74731b0db0f4dcbf51b2c11d4853 (diff)
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gh-95235: Add explicit parameter list to some sqlite3 methods (#95240)
Co-authored-by: CAM Gerlach <CAM.Gerlach@Gerlach.CAM>
Diffstat (limited to 'Doc/library/sqlite3.rst')
-rw-r--r--Doc/library/sqlite3.rst210
1 files changed, 143 insertions, 67 deletions
diff --git a/Doc/library/sqlite3.rst b/Doc/library/sqlite3.rst
index 956079b..b755494 100644
--- a/Doc/library/sqlite3.rst
+++ b/Doc/library/sqlite3.rst
@@ -286,7 +286,7 @@ Module functions and constants
Can be ``"DEFERRED"`` (default), ``"EXCLUSIVE"`` or ``"IMMEDIATE"``;
or :const:`None` to disable opening transactions implicitly.
See :ref:`sqlite3-controlling-transactions` for more.
- :type isolation_level: str | None
+ :type isolation_level: str | :const:`None`
:param check_same_thread:
If :const:`True` (default), only the creating thread may use the connection.
@@ -316,7 +316,7 @@ Module functions and constants
enabling various :ref:`sqlite3-uri-tricks`.
:type uri: bool
- :rtype: sqlite3.Connection
+ :rtype: Connection
.. audit-event:: sqlite3.connect database sqlite3.connect
.. audit-event:: sqlite3.connect/handle connection_handle sqlite3.connect
@@ -434,13 +434,36 @@ Connection Objects
.. method:: blobopen(table, column, row, /, *, readonly=False, name="main")
- Open a :class:`Blob` handle to the :abbr:`BLOB (Binary Large OBject)`
- located in table name *table*, column name *column*, and row index *row*
- of database *name*.
- When *readonly* is :const:`True` the blob is opened without write
- permissions.
- Trying to open a blob in a ``WITHOUT ROWID`` table will raise
- :exc:`OperationalError`.
+ Open a :class:`Blob` handle to an existing
+ :abbr:`BLOB (Binary Large OBject)`.
+
+ :param table:
+ The name of the table where the blob is located.
+ :type table: str
+
+ :param column:
+ The name of the column where the blob is located.
+ :type column: str
+
+ :param row:
+ The name of the row where the blob is located.
+ :type row: str
+
+ :param readonly:
+ Set to :const:`True` if the blob should be opened without write
+ permissions.
+ Defaults to :const:`False`.
+ :type readonly: bool
+
+ :param name:
+ The name of the database where the blob is located.
+ Defaults to ``"main"``.
+ :type name: str
+
+ :raises OperationalError:
+ When trying to open a blob in a ``WITHOUT ROWID`` table.
+
+ :rtype: Blob
.. note::
@@ -486,21 +509,35 @@ Connection Objects
.. method:: create_function(name, narg, func, *, deterministic=False)
- Creates a user-defined function that you can later use from within SQL
- statements under the function name *name*. *narg* is the number of
- parameters the function accepts (if *narg* is -1, the function may
- take any number of arguments), and *func* is a Python callable that is
- called as the SQL function. If *deterministic* is true, the created function
- is marked as `deterministic <https://sqlite.org/deterministic.html>`_, which
- allows SQLite to perform additional optimizations. This flag is supported by
- SQLite 3.8.3 or higher, :exc:`NotSupportedError` will be raised if used
- with older versions.
+ Create or remove a user-defined SQL function.
+
+ :param name:
+ The name of the SQL function.
+ :type name: str
+
+ :param narg:
+ The number of arguments the SQL function can accept.
+ If ``-1``, it may take any number of arguments.
+ :type narg: int
- The function can return any of
- :ref:`the types natively supported by SQLite <sqlite3-types>`.
+ :param func:
+ A callable that is called when the SQL function is invoked.
+ The callable must return :ref:`a type natively supported by SQLite
+ <sqlite3-types>`.
+ Set to :const:`None` to remove an existing SQL function.
+ :type func: :term:`callback` | :const:`None`
- .. versionchanged:: 3.8
- The *deterministic* parameter was added.
+ :param deterministic:
+ If :const:`True`, the created SQL function is marked as
+ `deterministic <https://sqlite.org/deterministic.html>`_,
+ which allows SQLite to perform additional optimizations.
+ :type deterministic: bool
+
+ :raises NotSupportedError:
+ If *deterministic* is used with SQLite versions older than 3.8.3.
+
+ .. versionadded:: 3.8
+ The *deterministic* parameter.
Example:
@@ -509,15 +546,29 @@ Connection Objects
.. method:: create_aggregate(name, /, n_arg, aggregate_class)
- Creates a user-defined aggregate function.
+ Create or remove a user-defined SQL aggregate function.
+
+ :param name:
+ The name of the SQL aggregate function.
+ :type name: str
- The aggregate class must implement a ``step`` method, which accepts the number
- of parameters *n_arg* (if *n_arg* is -1, the function may take
- any number of arguments), and a ``finalize`` method which will return the
- final result of the aggregate.
+ :param n_arg:
+ The number of arguments the SQL aggregate function can accept.
+ If ``-1``, it may take any number of arguments.
+ :type n_arg: int
- The ``finalize`` method can return any of
- :ref:`the types natively supported by SQLite <sqlite3-types>`.
+ :param aggregate_class:
+ A class must implement the following methods:
+
+ * ``step()``: Add a row to the aggregate.
+ * ``finalize()``: Return the final result of the aggregate as
+ :ref:`a type natively supported by SQLite <sqlite3-types>`.
+
+ The number of arguments that the ``step()`` method must accept
+ is controlled by *n_arg*.
+
+ Set to :const:`None` to remove an existing SQL aggregate function.
+ :type aggregate_class: :term:`class` | :const:`None`
Example:
@@ -526,25 +577,36 @@ Connection Objects
.. method:: create_window_function(name, num_params, aggregate_class, /)
- Creates user-defined aggregate window function *name*.
+ Create or remove a user-defined aggregate window function.
+
+ :param name:
+ The name of the SQL aggregate window function to create or remove.
+ :type name: str
+
+ :param num_params:
+ The number of arguments the SQL aggregate window function can accept.
+ If ``-1``, it may take any number of arguments.
+ :type num_params: int
+
+ :param aggregate_class:
+ A class that must implement the following methods:
- *aggregate_class* must implement the following methods:
+ * ``step()``: Add a row to the current window.
+ * ``value()``: Return the current value of the aggregate.
+ * ``inverse()``: Remove a row from the current window.
+ * ``finalize()``: Return the final result of the aggregate as
+ :ref:`a type natively supported by SQLite <sqlite3-types>`.
- * ``step``: adds a row to the current window
- * ``value``: returns the current value of the aggregate
- * ``inverse``: removes a row from the current window
- * ``finalize``: returns the final value of the aggregate
+ The number of arguments that the ``step()`` and ``value()`` methods
+ must accept is controlled by *num_params*.
- ``step`` and ``value`` accept *num_params* number of parameters,
- unless *num_params* is ``-1``, in which case they may take any number of
- arguments.
- ``finalize`` and ``value`` can return any of
- :ref:`the types natively supported by SQLite <sqlite3-types>`.
- Call :meth:`create_window_function` with
- *aggregate_class* set to :const:`None` to clear window function *name*.
+ Set to :const:`None` to remove an existing SQL aggregate window function.
- Aggregate window functions are supported by SQLite 3.25.0 and higher.
- :exc:`NotSupportedError` will be raised if used with older versions.
+ :raises NotSupportedError:
+ If used with a version of SQLite older than 3.25.0,
+ which does not support aggregate window functions.
+
+ :type aggregate_class: :term:`class` | :const:`None`
.. versionadded:: 3.11
@@ -744,29 +806,43 @@ Connection Objects
.. method:: backup(target, *, pages=-1, progress=None, name="main", sleep=0.250)
- This method makes a backup of an SQLite database even while it's being accessed
- by other clients, or concurrently by the same connection. The copy will be
- written into the mandatory argument *target*, that must be another
- :class:`Connection` instance.
-
- By default, or when *pages* is either ``0`` or a negative integer, the entire
- database is copied in a single step; otherwise the method performs a loop
- copying up to *pages* pages at a time.
-
- If *progress* is specified, it must either be ``None`` or a callable object that
- will be executed at each iteration with three integer arguments, respectively
- the *status* of the last iteration, the *remaining* number of pages still to be
- copied and the *total* number of pages.
-
- The *name* argument specifies the database name that will be copied: it must be
- a string containing either ``"main"``, the default, to indicate the main
- database, ``"temp"`` to indicate the temporary database or the name specified
- after the ``AS`` keyword in an ``ATTACH DATABASE`` statement for an attached
- database.
-
- The *sleep* argument specifies the number of seconds to sleep by between
- successive attempts to backup remaining pages, can be specified either as an
- integer or a floating point value.
+ Create a backup of an SQLite database.
+
+ Works even if the database is being accessed by other clients
+ or concurrently by the same connection.
+
+ :param target:
+ The database connection to save the backup to.
+ :type target: Connection
+
+ :param pages:
+ The number of pages to copy at a time.
+ If equal to or less than ``0``,
+ the entire database is copied in a single step.
+ Defaults to ``-1``.
+ :type pages: int
+
+ :param progress:
+ If set to a callable, it is invoked with three integer arguments for
+ every backup iteration:
+ the *status* of the last iteration,
+ the *remaining* number of pages still to be copied,
+ and the *total* number of pages.
+ Defaults to :const:`None`.
+ :type progress: :term:`callback` | :const:`None`
+
+ :param name:
+ The name of the database to back up.
+ Either ``"main"`` (the default) for the main database,
+ ``"temp"`` for the temporary database,
+ or the name of a custom database as attached using the
+ ``ATTACH DATABASE`` SQL statment.
+ :type name: str
+
+ :param sleep:
+ The number of seconds to sleep between successive attempts
+ to back up remaining pages.
+ :type sleep: float
Example 1, copy an existing database into another::