[3.10] gh-89018: Improve documentation of sqlite3 exceptions (GH-27645) (#93838)

erlend-aasland · web-flow · commit 56ee410053de · 2022-06-15T11:55:30.000+02:00
- Order exceptions as in PEP 249 - Reword descriptions, so they match the current behaviour Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>. (cherry picked from commit bb0b768) Co-authored-by: Erlend Egeberg Aasland <erlend.aasland@protonmail.com>
diff --git a/Doc/library/sqlite3.rst b/Doc/library/sqlite3.rst
@@ -681,7 +681,7 @@ Cursor Objects
       :ref:`placeholders <sqlite3-placeholders>`.
 
       :meth:`execute` will only execute a single SQL statement. If you try to execute
-      more than one statement with it, it will raise a :exc:`.Warning`. Use
+      more than one statement with it, it will raise a :exc:`Warning`. Use
       :meth:`executescript` if you want to execute multiple SQL statements with one
       call.
 
@@ -883,43 +883,74 @@ Now we plug :class:`Row` in::
 Exceptions
 ----------
 
+The exception hierarchy is defined by the DB-API 2.0 (:pep:`249`).
+
 .. exception:: Warning
 
-   A subclass of :exc:`Exception`.
+   This exception is raised by ``sqlite3`` if an SQL query is not a
+   :class:`string <str>`, or if multiple statements are passed to
+   :meth:`~Cursor.execute` or :meth:`~Cursor.executemany`.
+   ``Warning`` is a subclass of :exc:`Exception`.
 
 .. exception:: Error
 
-   The base class of the other exceptions in this module.  It is a subclass
-   of :exc:`Exception`.
+   The base class of the other exceptions in this module.
+   Use this to catch all errors with one single :keyword:`except` statement.
+   ``Error`` is a subclass of :exc:`Exception`.
+
+.. exception:: InterfaceError
+
+   This exception is raised by ``sqlite3`` for fetch across rollback,
+   or if ``sqlite3`` is unable to bind parameters.
+   ``InterfaceError`` is a subclass of :exc:`Error`.
 
 .. exception:: DatabaseError
 
    Exception raised for errors that are related to the database.
+   This serves as the base exception for several types of database errors.
+   It is only raised implicitly through the specialised subclasses.
+   ``DatabaseError`` is a subclass of :exc:`Error`.
+
+.. exception:: DataError
+
+   Exception raised for errors caused by problems with the processed data,
+   like numeric values out of range, and strings which are too long.
+   ``DataError`` is a subclass of :exc:`DatabaseError`.
+
+.. exception:: OperationalError
+
+   Exception raised for errors that are related to the database's operation,
+   and not necessarily under the control of the programmer.
+   For example, the database path is not found,
+   or a transaction could not be processed.
+   ``OperationalError`` is a subclass of :exc:`DatabaseError`.
 
 .. exception:: IntegrityError
 
    Exception raised when the relational integrity of the database is affected,
    e.g. a foreign key check fails.  It is a subclass of :exc:`DatabaseError`.
 
-.. exception:: ProgrammingError
+.. exception:: InternalError
 
-   Exception raised for programming errors, e.g. table not found or already
-   exists, syntax error in the SQL statement, wrong number of parameters
-   specified, etc.  It is a subclass of :exc:`DatabaseError`.
+   Exception raised when SQLite encounters an internal error.
+   If this is raised, it may indicate that there is a problem with the runtime
+   SQLite library.
+   ``InternalError`` is a subclass of :exc:`DatabaseError`.
 
-.. exception:: OperationalError
+.. exception:: ProgrammingError
 
-   Exception raised for errors that are related to the database's operation
-   and not necessarily under the control of the programmer, e.g. an unexpected
-   disconnect occurs, the data source name is not found, a transaction could
-   not be processed, etc.  It is a subclass of :exc:`DatabaseError`.
+   Exception raised for ``sqlite3`` API programming errors,
+   for example trying to operate on a closed :class:`Connection`,
+   or trying to execute non-DML statements with :meth:`~Cursor.executemany`.
+   ``ProgrammingError`` is a subclass of :exc:`DatabaseError`.
 
 .. exception:: NotSupportedError
 
-   Exception raised in case a method or database API was used which is not
-   supported by the database, e.g. calling the :meth:`~Connection.rollback`
-   method on a connection that does not support transaction or has
-   transactions turned off.  It is a subclass of :exc:`DatabaseError`.
+   Exception raised in case a method or database API is not supported by the
+   underlying SQLite library. For example, setting *deterministic* to
+   :const:`True` in :meth:`~Connection.create_function`, if the underlying SQLite library
+   does not support deterministic functions.
+   ``NotSupportedError`` is a subclass of :exc:`DatabaseError`.
 
 
 .. _sqlite3-types:
