diff options
| author | Kali Kaneko <kali@futeisha.org> | 2013-02-04 19:20:12 +0900 | 
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| committer | Kali Kaneko <kali@futeisha.org> | 2013-02-04 19:20:12 +0900 | 
| commit | 4189e53a881e52de0945375a72b8748143c5bd13 (patch) | |
| tree | 23ed8e0600dc3c62da7a95e50f778c79a9be1e75 /doc/sphinx | |
initial commit
Diffstat (limited to 'doc/sphinx')
| -rw-r--r-- | doc/sphinx/.static/.keepme | 0 | ||||
| -rw-r--r-- | doc/sphinx/Makefile | 66 | ||||
| -rw-r--r-- | doc/sphinx/conf.py | 132 | ||||
| -rw-r--r-- | doc/sphinx/index.rst | 19 | ||||
| -rw-r--r-- | doc/sphinx/sqlite3.rst | 886 | 
5 files changed, 1103 insertions, 0 deletions
diff --git a/doc/sphinx/.static/.keepme b/doc/sphinx/.static/.keepme new file mode 100644 index 0000000..e69de29 --- /dev/null +++ b/doc/sphinx/.static/.keepme diff --git a/doc/sphinx/Makefile b/doc/sphinx/Makefile new file mode 100644 index 0000000..bccfdaf --- /dev/null +++ b/doc/sphinx/Makefile @@ -0,0 +1,66 @@ +# Makefile for Sphinx documentation +# + +# You can set these variables from the command line. +SPHINXOPTS   = +SPHINXBUILD  = sphinx-build +PAPER        = + +ALLSPHINXOPTS = -d .build/doctrees -D latex_paper_size=$(PAPER) \ +                $(SPHINXOPTS) . + +.PHONY: help clean html web htmlhelp latex changes linkcheck + +help: +	@echo "Please use \`make <target>' where <target> is one of" +	@echo "  html      to make standalone HTML files" +	@echo "  web       to make files usable by Sphinx.web" +	@echo "  htmlhelp  to make HTML files and a HTML help project" +	@echo "  latex     to make LaTeX files, you can set PAPER=a4 or PAPER=letter" +	@echo "  changes   to make an overview over all changed/added/deprecated items" +	@echo "  linkcheck to check all external links for integrity" + +clean: +	-rm -rf .build/* + +html: +	mkdir -p .build/html .build/doctrees +	$(SPHINXBUILD) -b html $(ALLSPHINXOPTS) .build/html +	@echo +	@echo "Build finished. The HTML pages are in .build/html." + +web: +	mkdir -p .build/web .build/doctrees +	$(SPHINXBUILD) -b web $(ALLSPHINXOPTS) .build/web +	@echo +	@echo "Build finished; now you can run" +	@echo "  python -m sphinx.web .build/web" +	@echo "to start the server." + +htmlhelp: +	mkdir -p .build/htmlhelp .build/doctrees +	$(SPHINXBUILD) -b htmlhelp $(ALLSPHINXOPTS) .build/htmlhelp +	@echo +	@echo "Build finished; now you can run HTML Help Workshop with the" \ +	      ".hhp project file in .build/htmlhelp." + +latex: +	mkdir -p .build/latex .build/doctrees +	$(SPHINXBUILD) -b latex $(ALLSPHINXOPTS) .build/latex +	@echo +	@echo "Build finished; the LaTeX files are in .build/latex." +	@echo "Run \`make all-pdf' or \`make all-ps' in that directory to" \ +	      "run these through (pdf)latex." + +changes: +	mkdir -p .build/changes .build/doctrees +	$(SPHINXBUILD) -b changes $(ALLSPHINXOPTS) .build/changes +	@echo +	@echo "The overview file is in .build/changes." + +linkcheck: +	mkdir -p .build/linkcheck .build/doctrees +	$(SPHINXBUILD) -b linkcheck $(ALLSPHINXOPTS) .build/linkcheck +	@echo +	@echo "Link check complete; look for any errors in the above output " \ +	      "or in .build/linkcheck/output.txt." diff --git a/doc/sphinx/conf.py b/doc/sphinx/conf.py new file mode 100644 index 0000000..6528513 --- /dev/null +++ b/doc/sphinx/conf.py @@ -0,0 +1,132 @@ +# -*- coding: utf-8 -*- +# +# pysqlite documentation build configuration file, created by +# sphinx-quickstart.py on Sat Mar 22 02:47:54 2008. +# +# This file is execfile()d with the current directory set to its containing dir. +# +# The contents of this file are pickled, so don't put values in the namespace +# that aren't pickleable (module imports are okay, they're removed automatically). +# +# All configuration values have a default value; values that are commented out +# serve to show the default value. + +import sys + +# If your extensions are in another directory, add it here. +#sys.path.append('some/directory') + +# General configuration +# --------------------- + +# Add any Sphinx extension module names here, as strings. They can be extensions +# coming with Sphinx (named 'sphinx.addons.*') or your custom ones. +#extensions = [] + +# Add any paths that contain templates here, relative to this directory. +templates_path = ['.templates'] + +# The suffix of source filenames. +source_suffix = '.rst' + +# The master toctree document. +master_doc = 'index' + +# General substitutions. +project = 'pysqlite' +copyright = u'2008-2009, Gerhard Häring' + +# The default replacements for |version| and |release|, also used in various +# other places throughout the built documents. +# +# The short X.Y version. +version = '2.6' +# The full version, including alpha/beta/rc tags. +release = '2.6.0' + +# There are two options for replacing |today|: either, you set today to some +# non-false value, then it is used: +#today = '' +# Else, today_fmt is used as the format for a strftime call. +today_fmt = '%B %d, %Y' + +# List of documents that shouldn't be included in the build. +#unused_docs = [] + +# If true, '()' will be appended to :func: etc. cross-reference text. +#add_function_parentheses = True + +# If true, the current module name will be prepended to all description +# unit titles (such as .. function::). +#add_module_names = True + +# If true, sectionauthor and moduleauthor directives will be shown in the +# output. They are ignored by default. +#show_authors = False + +# The name of the Pygments (syntax highlighting) style to use. +pygments_style = 'sphinx' + + +# Options for HTML output +# ----------------------- + +# The style sheet to use for HTML and HTML Help pages. A file of that name +# must exist either in Sphinx' static/ path, or in one of the custom paths +# given in html_static_path. +html_style = 'default.css' + +# Add any paths that contain custom static files (such as style sheets) here, +# relative to this directory. They are copied after the builtin static files, +# so a file named "default.css" will overwrite the builtin "default.css". +html_static_path = ['.static'] + +# If not '', a 'Last updated on:' timestamp is inserted at every page bottom, +# using the given strftime format. +html_last_updated_fmt = '%b %d, %Y' + +# If true, SmartyPants will be used to convert quotes and dashes to +# typographically correct entities. +#html_use_smartypants = True + +# Content template for the index page. +#html_index = '' + +# Custom sidebar templates, maps document names to template names. +#html_sidebars = {} + +# Additional templates that should be rendered to pages, maps page names to +# template names. +#html_additional_pages = {} + +# If false, no module index is generated. +#html_use_modindex = True + +# If true, the reST sources are included in the HTML build as _sources/<name>. +#html_copy_source = True + +# Output file base name for HTML help builder. +htmlhelp_basename = 'pysqlitedoc' + + +# Options for LaTeX output +# ------------------------ + +# The paper size ('letter' or 'a4'). +#latex_paper_size = 'letter' + +# The font size ('10pt', '11pt' or '12pt'). +#latex_font_size = '10pt' + +# Grouping the document tree into LaTeX files. List of tuples +# (source start file, target name, title, author, document class [howto/manual]). +#latex_documents = [] + +# Additional stuff for the LaTeX preamble. +#latex_preamble = '' + +# Documents to append as an appendix to all manuals. +#latex_appendices = [] + +# If false, no module index is generated. +#latex_use_modindex = True diff --git a/doc/sphinx/index.rst b/doc/sphinx/index.rst new file mode 100644 index 0000000..522f986 --- /dev/null +++ b/doc/sphinx/index.rst @@ -0,0 +1,19 @@ +.. pysqlite documentation master file, created by sphinx-quickstart.py on Sat Mar 22 02:47:54 2008. +   You can adapt this file completely to your liking, but it should at least +   contain the root `toctree` directive. + +Welcome to pysqlite's documentation! +==================================== + +Contents: + +.. toctree:: +   :maxdepth: 2 + +Indices and tables +================== + +* :ref:`genindex` +* :ref:`modindex` +* :ref:`search` + diff --git a/doc/sphinx/sqlite3.rst b/doc/sphinx/sqlite3.rst new file mode 100644 index 0000000..a0d5de8 --- /dev/null +++ b/doc/sphinx/sqlite3.rst @@ -0,0 +1,886 @@ +:mod:`sqlite3` --- DB-API 2.0 interface for SQLite databases +============================================================ + +.. module:: sqlite3 +   :synopsis: A DB-API 2.0 implementation using SQLite 3.x. +.. sectionauthor:: Gerhard Häring <gh@ghaering.de> + + +SQLite is a C library that provides a lightweight disk-based database that +doesn't require a separate server process and allows accessing the database +using a nonstandard variant of the SQL query language. Some applications can use +SQLite for internal data storage.  It's also possible to prototype an +application using SQLite and then port the code to a larger database such as +PostgreSQL or Oracle. + +pysqlite was written by Gerhard Häring and provides a SQL interface compliant +with the DB-API 2.0 specification described by :pep:`249`. + +To use the module, you must first create a :class:`Connection` object that +represents the database.  Here the data will be stored in the +:file:`/tmp/example` file:: + +   conn = sqlite3.connect('/tmp/example') + +You can also supply the special name ``:memory:`` to create a database in RAM. + +Once you have a :class:`Connection`, you can create a :class:`Cursor`  object +and call its :meth:`~Cursor.execute` method to perform SQL commands:: + +   c = conn.cursor() + +   # Create table +   c.execute('''create table stocks +   (date text, trans text, symbol text, +    qty real, price real)''') + +   # Insert a row of data +   c.execute("""insert into stocks +             values ('2006-01-05','BUY','RHAT',100,35.14)""") + +   # Save (commit) the changes +   conn.commit() + +   # We can also close the cursor if we are done with it +   c.close() + +Usually your SQL operations will need to use values from Python variables.  You +shouldn't assemble your query using Python's string operations because doing so +is insecure; it makes your program vulnerable to an SQL injection attack. + +Instead, use the DB-API's parameter substitution.  Put ``?`` as a placeholder +wherever you want to use a value, and then provide a tuple of values as the +second argument to the cursor's :meth:`~Cursor.execute` method.  (Other database +modules may use a different placeholder, such as ``%s`` or ``:1``.) For +example:: + +   # Never do this -- insecure! +   symbol = 'IBM' +   c.execute("... where symbol = '%s'" % symbol) + +   # Do this instead +   t = (symbol,) +   c.execute('select * from stocks where symbol=?', t) + +   # Larger example +   for t in [('2006-03-28', 'BUY', 'IBM', 1000, 45.00), +             ('2006-04-05', 'BUY', 'MSOFT', 1000, 72.00), +             ('2006-04-06', 'SELL', 'IBM', 500, 53.00), +            ]: +       c.execute('insert into stocks values (?,?,?,?,?)', t) + +To retrieve data after executing a SELECT statement, you can either treat the +cursor as an :term:`iterator`, call the cursor's :meth:`~Cursor.fetchone` method to +retrieve a single matching row, or call :meth:`~Cursor.fetchall` to get a list of the +matching rows. + +This example uses the iterator form:: + +   >>> c = conn.cursor() +   >>> c.execute('select * from stocks order by price') +   >>> for row in c: +   ...    print row +   ... +   (u'2006-01-05', u'BUY', u'RHAT', 100, 35.14) +   (u'2006-03-28', u'BUY', u'IBM', 1000, 45.0) +   (u'2006-04-06', u'SELL', u'IBM', 500, 53.0) +   (u'2006-04-05', u'BUY', u'MSOFT', 1000, 72.0) +   >>> + + +.. seealso:: + +   http://code.google.com/p/pysqlite/ +      The pysqlite web page -- sqlite3 is developed externally under the name +      "pysqlite". + +   http://www.sqlite.org +      The SQLite web page; the documentation describes the syntax and the +      available data types for the supported SQL dialect. + +   :pep:`249` - Database API Specification 2.0 +      PEP written by Marc-André Lemburg. + + +.. _sqlite3-module-contents: + +Module functions and constants +------------------------------ + + +.. data:: PARSE_DECLTYPES + +   This constant is meant to be used with the *detect_types* parameter of the +   :func:`connect` function. + +   Setting it makes the :mod:`sqlite3` module parse the declared type for each +   column it returns.  It will parse out the first word of the declared type, +   i. e.  for "integer primary key", it will parse out "integer", or for +   "number(10)" it will parse out "number". Then for that column, it will look +   into the converters dictionary and use the converter function registered for +   that type there. + + +.. data:: PARSE_COLNAMES + +   This constant is meant to be used with the *detect_types* parameter of the +   :func:`connect` function. + +   Setting this makes the SQLite interface parse the column name for each column it +   returns.  It will look for a string formed [mytype] in there, and then decide +   that 'mytype' is the type of the column. It will try to find an entry of +   'mytype' in the converters dictionary and then use the converter function found +   there to return the value. The column name found in :attr:`Cursor.description` +   is only the first word of the column name, i.  e. if you use something like +   ``'as "x [datetime]"'`` in your SQL, then we will parse out everything until the +   first blank for the column name: the column name would simply be "x". + + +.. function:: connect(database[, timeout, isolation_level, detect_types, factory]) + +   Opens a connection to the SQLite database file *database*. You can use +   ``":memory:"`` to open a database connection to a database that resides in RAM +   instead of on disk. + +   When a database is accessed by multiple connections, and one of the processes +   modifies the database, the SQLite database is locked until that transaction is +   committed. The *timeout* parameter specifies how long the connection should wait +   for the lock to go away until raising an exception. The default for the timeout +   parameter is 5.0 (five seconds). + +   For the *isolation_level* parameter, please see the +   :attr:`Connection.isolation_level` property of :class:`Connection` objects. + +   SQLite natively supports only the types TEXT, INTEGER, FLOAT, BLOB and NULL. If +   you want to use other types you must add support for them yourself. The +   *detect_types* parameter and the using custom **converters** registered with the +   module-level :func:`register_converter` function allow you to easily do that. + +   *detect_types* defaults to 0 (i. e. off, no type detection), you can set it to +   any combination of :const:`PARSE_DECLTYPES` and :const:`PARSE_COLNAMES` to turn +   type detection on. + +   By default, the :mod:`sqlite3` module uses its :class:`Connection` class for the +   connect call.  You can, however, subclass the :class:`Connection` class and make +   :func:`connect` use your class instead by providing your class for the *factory* +   parameter. + +   Consult the section :ref:`sqlite3-types` of this manual for details. + +   The :mod:`sqlite3` module internally uses a statement cache to avoid SQL parsing +   overhead. If you want to explicitly set the number of statements that are cached +   for the connection, you can set the *cached_statements* parameter. The currently +   implemented default is to cache 100 statements. + + +.. function:: register_converter(typename, callable) + +   Registers a callable to convert a bytestring from the database into a custom +   Python type. The callable will be invoked for all database values that are of +   the type *typename*. Confer the parameter *detect_types* of the :func:`connect` +   function for how the type detection works. Note that the case of *typename* and +   the name of the type in your query must match! + + +.. function:: register_adapter(type, callable) + +   Registers a callable to convert the custom Python type *type* into one of +   SQLite's supported types. The callable *callable* accepts as single parameter +   the Python value, and must return a value of the following types: int, long, +   float, str (UTF-8 encoded), unicode or buffer. + + +.. function:: complete_statement(sql) + +   Returns :const:`True` if the string *sql* contains one or more complete SQL +   statements terminated by semicolons. It does not verify that the SQL is +   syntactically correct, only that there are no unclosed string literals and the +   statement is terminated by a semicolon. + +   This can be used to build a shell for SQLite, as in the following example: + + +   .. literalinclude:: ../includes/sqlite3/complete_statement.py + + +.. function:: enable_callback_tracebacks(flag) + +   By default you will not get any tracebacks in user-defined functions, +   aggregates, converters, authorizer callbacks etc. If you want to debug them, you +   can call this function with *flag* as True. Afterwards, you will get tracebacks +   from callbacks on ``sys.stderr``. Use :const:`False` to disable the feature +   again. + + +.. _sqlite3-connection-objects: + +Connection Objects +------------------ + +.. class:: Connection + +   A SQLite database connection has the following attributes and methods: + +.. attribute:: Connection.isolation_level + +   Get or set the current isolation level. :const:`None` for autocommit mode or +   one of "DEFERRED", "IMMEDIATE" or "EXCLUSIVE". See section +   :ref:`sqlite3-controlling-transactions` for a more detailed explanation. + + +.. method:: Connection.cursor([cursorClass]) + +   The cursor method accepts a single optional parameter *cursorClass*. If +   supplied, this must be a custom cursor class that extends +   :class:`sqlite3.Cursor`. + + +.. method:: Connection.commit() + +   This method commits the current transaction. If you don't call this method, +   anything you did since the last call to ``commit()`` is not visible from from +   other database connections. If you wonder why you don't see the data you've +   written to the database, please check you didn't forget to call this method. + +.. method:: Connection.rollback() + +   This method rolls back any changes to the database since the last call to +   :meth:`commit`. + +.. method:: Connection.close() + +   This closes the database connection. Note that this does not automatically +   call :meth:`commit`. If you just close your database connection without +   calling :meth:`commit` first, your changes will be lost! + +.. method:: Connection.execute(sql, [parameters]) + +   This is a nonstandard shortcut that creates an intermediate cursor object by +   calling the cursor method, then calls the cursor's +   :meth:`execute<Cursor.execute>` method with the parameters given. + + +.. method:: Connection.executemany(sql, [parameters]) + +   This is a nonstandard shortcut that creates an intermediate cursor object by +   calling the cursor method, then calls the cursor's +   :meth:`executemany<Cursor.executemany>` method with the parameters given. + +.. method:: Connection.executescript(sql_script) + +   This is a nonstandard shortcut that creates an intermediate cursor object by +   calling the cursor method, then calls the cursor's +   :meth:`executescript<Cursor.executescript>` method with the parameters +   given. + + +.. method:: Connection.create_function(name, num_params, func) + +   Creates a user-defined function that you can later use from within SQL +   statements under the function name *name*. *num_params* is the number of +   parameters the function accepts, and *func* is a Python callable that is called +   as the SQL function. + +   The function can return any of the types supported by SQLite: unicode, str, int, +   long, float, buffer and None. + +   Example: + +   .. literalinclude:: ../includes/sqlite3/md5func.py + + +.. method:: Connection.create_aggregate(name, num_params, aggregate_class) + +   Creates a user-defined aggregate function. + +   The aggregate class must implement a ``step`` method, which accepts the number +   of parameters *num_params*, and a ``finalize`` method which will return the +   final result of the aggregate. + +   The ``finalize`` method can return any of the types supported by SQLite: +   unicode, str, int, long, float, buffer and None. + +   Example: + +   .. literalinclude:: ../includes/sqlite3/mysumaggr.py + + +.. method:: Connection.create_collation(name, callable) + +   Creates a collation with the specified *name* and *callable*. The callable will +   be passed two string arguments. It should return -1 if the first is ordered +   lower than the second, 0 if they are ordered equal and 1 if the first is ordered +   higher than the second.  Note that this controls sorting (ORDER BY in SQL) so +   your comparisons don't affect other SQL operations. + +   Note that the callable will get its parameters as Python bytestrings, which will +   normally be encoded in UTF-8. + +   The following example shows a custom collation that sorts "the wrong way": + +   .. literalinclude:: ../includes/sqlite3/collation_reverse.py + +   To remove a collation, call ``create_collation`` with None as callable:: + +      con.create_collation("reverse", None) + + +.. method:: Connection.interrupt() + +   You can call this method from a different thread to abort any queries that might +   be executing on the connection. The query will then abort and the caller will +   get an exception. + + +.. method:: Connection.set_authorizer(authorizer_callback) + +   This routine registers a callback. The callback is invoked for each attempt to +   access a column of a table in the database. The callback should return +   :const:`SQLITE_OK` if access is allowed, :const:`SQLITE_DENY` if the entire SQL +   statement should be aborted with an error and :const:`SQLITE_IGNORE` if the +   column should be treated as a NULL value. These constants are available in the +   :mod:`sqlite3` module. + +   The first argument to the callback signifies what kind of operation is to be +   authorized. The second and third argument will be arguments or :const:`None` +   depending on the first argument. The 4th argument is the name of the database +   ("main", "temp", etc.) if applicable. The 5th argument is the name of the +   inner-most trigger or view that is responsible for the access attempt or +   :const:`None` if this access attempt is directly from input SQL code. + +   Please consult the SQLite documentation about the possible values for the first +   argument and the meaning of the second and third argument depending on the first +   one. All necessary constants are available in the :mod:`sqlite3` module. + + +.. method:: Connection.set_progress_handler(handler, n) + +   This routine registers a callback. The callback is invoked for every *n* +   instructions of the SQLite virtual machine. This is useful if you want to +   get called from SQLite during long-running operations, for example to update +   a GUI. + +   If you want to clear any previously installed progress handler, call the +   method with :const:`None` for *handler*. + + +.. method:: Connection.enable_load_extension(enabled) + +   This routine allows/disallows the SQLite engine to load SQLite extensions +   from shared libraries.  SQLite extensions can define new functions, +   aggregates or whole new virtual table implementations. One well-known +   extension is the fulltext-search extension distributed with SQLite. + +   .. literalinclude:: ../includes/sqlite3/load_extension.py + +.. method:: Connection.load_extension(path) + +   This routine loads a SQLite extension from a shared library. You have to +   enable extension loading with ``enable_load_extension`` before you can use +   this routine. + +.. attribute:: Connection.row_factory + +   You can change this attribute to a callable that accepts the cursor and the +   original row as a tuple and will return the real result row.  This way, you can +   implement more advanced ways of returning results, such  as returning an object +   that can also access columns by name. + +   Example: + +   .. literalinclude:: ../includes/sqlite3/row_factory.py + +   If returning a tuple doesn't suffice and you want name-based access to +   columns, you should consider setting :attr:`row_factory` to the +   highly-optimized :class:`sqlite3.Row` type. :class:`Row` provides both +   index-based and case-insensitive name-based access to columns with almost no +   memory overhead. It will probably be better than your own custom +   dictionary-based approach or even a db_row based solution. + +   .. XXX what's a db_row-based solution? + + +.. attribute:: Connection.text_factory + +   Using this attribute you can control what objects are returned for the ``TEXT`` +   data type. By default, this attribute is set to :class:`unicode` and the +   :mod:`sqlite3` module will return Unicode objects for ``TEXT``. If you want to +   return bytestrings instead, you can set it to :class:`str`. + +   For efficiency reasons, there's also a way to return Unicode objects only for +   non-ASCII data, and bytestrings otherwise. To activate it, set this attribute to +   :const:`sqlite3.OptimizedUnicode`. + +   You can also set it to any other callable that accepts a single bytestring +   parameter and returns the resulting object. + +   See the following example code for illustration: + +   .. literalinclude:: ../includes/sqlite3/text_factory.py + + +.. attribute:: Connection.total_changes + +   Returns the total number of database rows that have been modified, inserted, or +   deleted since the database connection was opened. + + +.. attribute:: Connection.iterdump + +   Returns an iterator to dump the database in an SQL text format.  Useful when +   saving an in-memory database for later restoration.  This function provides +   the same capabilities as the :kbd:`.dump` command in the :program:`sqlite3` +   shell. + +   Example:: + +      # Convert file existing_db.db to SQL dump file dump.sql +      import sqlite3, os + +      con = sqlite3.connect('existing_db.db') +      full_dump = os.linesep.join([line for line in con.iterdump()]) +      f = open('dump.sql', 'w') +      f.writelines(full_dump) +      f.close() + + +.. _sqlite3-cursor-objects: + +Cursor Objects +-------------- + +A :class:`Cursor` instance has the following attributes and methods: + +   A SQLite database cursor has the following attributes and methods: + +.. method:: Cursor.execute(sql, [parameters]) + +   Executes an SQL statement. The SQL statement may be parametrized (i. e. +   placeholders instead of SQL literals). The :mod:`sqlite3` module supports two +   kinds of placeholders: question marks (qmark style) and named placeholders +   (named style). + +   This example shows how to use parameters with qmark style: + +   .. literalinclude:: ../includes/sqlite3/execute_1.py + +   This example shows how to use the named style: + +   .. literalinclude:: ../includes/sqlite3/execute_2.py + +   :meth:`execute` will only execute a single SQL statement. If you try to execute +   more than one statement with it, it will raise a Warning. Use +   :meth:`executescript` if you want to execute multiple SQL statements with one +   call. + + +.. method:: Cursor.executemany(sql, seq_of_parameters) + +   Executes an SQL command against all parameter sequences or mappings found in +   the sequence *sql*.  The :mod:`sqlite3` module also allows using an +   :term:`iterator` yielding parameters instead of a sequence. + +   .. literalinclude:: ../includes/sqlite3/executemany_1.py + +   Here's a shorter example using a :term:`generator`: + +   .. literalinclude:: ../includes/sqlite3/executemany_2.py + + +.. method:: Cursor.executescript(sql_script) + +   This is a nonstandard convenience method for executing multiple SQL statements +   at once. It issues a ``COMMIT`` statement first, then executes the SQL script it +   gets as a parameter. + +   *sql_script* can be a bytestring or a Unicode string. + +   Example: + +   .. literalinclude:: ../includes/sqlite3/executescript.py + + +.. method:: Cursor.fetchone() + +   Fetches the next row of a query result set, returning a single sequence, +   or :const:`None` when no more data is available. + + +.. method:: Cursor.fetchmany([size=cursor.arraysize]) + +   Fetches the next set of rows of a query result, returning a list.  An empty +   list is returned when no more rows are available. + +   The number of rows to fetch per call is specified by the *size* parameter. +   If it is not given, the cursor's arraysize determines the number of rows +   to be fetched. The method should try to fetch as many rows as indicated by +   the size parameter. If this is not possible due to the specified number of +   rows not being available, fewer rows may be returned. + +   Note there are performance considerations involved with the *size* parameter. +   For optimal performance, it is usually best to use the arraysize attribute. +   If the *size* parameter is used, then it is best for it to retain the same +   value from one :meth:`fetchmany` call to the next. + +.. method:: Cursor.fetchall() + +   Fetches all (remaining) rows of a query result, returning a list.  Note that +   the cursor's arraysize attribute can affect the performance of this operation. +   An empty list is returned when no rows are available. + + +.. attribute:: Cursor.rowcount + +   Although the :class:`Cursor` class of the :mod:`sqlite3` module implements this +   attribute, the database engine's own support for the determination of "rows +   affected"/"rows selected" is quirky. + +   For ``DELETE`` statements, SQLite reports :attr:`rowcount` as 0 if you make a +   ``DELETE FROM table`` without any condition. + +   For :meth:`executemany` statements, the number of modifications are summed up +   into :attr:`rowcount`. + +   As required by the Python DB API Spec, the :attr:`rowcount` attribute "is -1 in +   case no ``executeXX()`` has been performed on the cursor or the rowcount of the +   last operation is not determinable by the interface". + +   This includes ``SELECT`` statements because we cannot determine the number of +   rows a query produced until all rows were fetched. + +.. attribute:: Cursor.lastrowid + +   This read-only attribute provides the rowid of the last modified row. It is +   only set if you issued a ``INSERT`` statement using the :meth:`execute` +   method. For operations other than ``INSERT`` or when :meth:`executemany` is +   called, :attr:`lastrowid` is set to :const:`None`. + +.. attribute:: Cursor.description + +   This read-only attribute provides the column names of the last query. To +   remain compatible with the Python DB API, it returns a 7-tuple for each +   column where the last six items of each tuple are :const:`None`. + +   It is set for ``SELECT`` statements without any matching rows as well. + +.. _sqlite3-row-objects: + +Row Objects +----------- + +.. class:: Row + +   A :class:`Row` instance serves as a highly optimized +   :attr:`~Connection.row_factory` for :class:`Connection` objects. +   It tries to mimic a tuple in most of its features. + +   It supports mapping access by column name and index, iteration, +   representation, equality testing and :func:`len`. + +   If two :class:`Row` objects have exactly the same columns and their +   members are equal, they compare equal. + +   .. versionchanged:: 2.6 +      Added iteration and equality (hashability). + +   .. method:: keys + +      This method returns a tuple of column names. Immediately after a query, +      it is the first member of each tuple in :attr:`Cursor.description`. + +      .. versionadded:: 2.6 + +Let's assume we initialize a table as in the example given above:: + +    conn = sqlite3.connect(":memory:") +    c = conn.cursor() +    c.execute('''create table stocks +    (date text, trans text, symbol text, +     qty real, price real)''') +    c.execute("""insert into stocks +              values ('2006-01-05','BUY','RHAT',100,35.14)""") +    conn.commit() +    c.close() + +Now we plug :class:`Row` in:: + +    >>> conn.row_factory = sqlite3.Row +    >>> c = conn.cursor() +    >>> c.execute('select * from stocks') +    <sqlite3.Cursor object at 0x7f4e7dd8fa80> +    >>> r = c.fetchone() +    >>> type(r) +    <type 'sqlite3.Row'> +    >>> r +    (u'2006-01-05', u'BUY', u'RHAT', 100.0, 35.14) +    >>> len(r) +    5 +    >>> r[2] +    u'RHAT' +    >>> r.keys() +    ['date', 'trans', 'symbol', 'qty', 'price'] +    >>> r['qty'] +    100.0 +    >>> for member in r: print member +    ... +    2006-01-05 +    BUY +    RHAT +    100.0 +    35.14 + + +.. _sqlite3-types: + +SQLite and Python types +----------------------- + + +Introduction +^^^^^^^^^^^^ + +SQLite natively supports the following types: ``NULL``, ``INTEGER``, +``REAL``, ``TEXT``, ``BLOB``. + +The following Python types can thus be sent to SQLite without any problem: + ++-----------------------------+-------------+ +| Python type                 | SQLite type | ++=============================+=============+ +| :const:`None`               | ``NULL``    | ++-----------------------------+-------------+ +| :class:`int`                | ``INTEGER`` | ++-----------------------------+-------------+ +| :class:`long`               | ``INTEGER`` | ++-----------------------------+-------------+ +| :class:`float`              | ``REAL``    | ++-----------------------------+-------------+ +| :class:`str` (UTF8-encoded) | ``TEXT``    | ++-----------------------------+-------------+ +| :class:`unicode`            | ``TEXT``    | ++-----------------------------+-------------+ +| :class:`buffer`             | ``BLOB``    | ++-----------------------------+-------------+ + +This is how SQLite types are converted to Python types by default: + ++-------------+----------------------------------------------+ +| SQLite type | Python type                                  | ++=============+==============================================+ +| ``NULL``    | :const:`None`                                | ++-------------+----------------------------------------------+ +| ``INTEGER`` | :class:`int` or :class:`long`,               | +|             | depending on size                            | ++-------------+----------------------------------------------+ +| ``REAL``    | :class:`float`                               | ++-------------+----------------------------------------------+ +| ``TEXT``    | depends on :attr:`~Connection.text_factory`, | +|             | :class:`unicode` by default                  | ++-------------+----------------------------------------------+ +| ``BLOB``    | :class:`buffer`                              | ++-------------+----------------------------------------------+ + +The type system of the :mod:`sqlite3` module is extensible in two ways: you can +store additional Python types in a SQLite database via object adaptation, and +you can let the :mod:`sqlite3` module convert SQLite types to different Python +types via converters. + + +Using adapters to store additional Python types in SQLite databases +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +As described before, SQLite supports only a limited set of types natively. To +use other Python types with SQLite, you must **adapt** them to one of the +sqlite3 module's supported types for SQLite: one of NoneType, int, long, float, +str, unicode, buffer. + +The :mod:`sqlite3` module uses Python object adaptation, as described in +:pep:`246` for this.  The protocol to use is :class:`PrepareProtocol`. + +There are two ways to enable the :mod:`sqlite3` module to adapt a custom Python +type to one of the supported ones. + + +Letting your object adapt itself +"""""""""""""""""""""""""""""""" + +This is a good approach if you write the class yourself. Let's suppose you have +a class like this:: + +   class Point(object): +       def __init__(self, x, y): +           self.x, self.y = x, y + +Now you want to store the point in a single SQLite column.  First you'll have to +choose one of the supported types first to be used for representing the point. +Let's just use str and separate the coordinates using a semicolon. Then you need +to give your class a method ``__conform__(self, protocol)`` which must return +the converted value. The parameter *protocol* will be :class:`PrepareProtocol`. + +.. literalinclude:: ../includes/sqlite3/adapter_point_1.py + + +Registering an adapter callable +""""""""""""""""""""""""""""""" + +The other possibility is to create a function that converts the type to the +string representation and register the function with :meth:`register_adapter`. + +.. note:: + +   The type/class to adapt must be a :term:`new-style class`, i. e. it must have +   :class:`object` as one of its bases. + +.. literalinclude:: ../includes/sqlite3/adapter_point_2.py + +The :mod:`sqlite3` module has two default adapters for Python's built-in +:class:`datetime.date` and :class:`datetime.datetime` types.  Now let's suppose +we want to store :class:`datetime.datetime` objects not in ISO representation, +but as a Unix timestamp. + +.. literalinclude:: ../includes/sqlite3/adapter_datetime.py + + +Converting SQLite values to custom Python types +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +Writing an adapter lets you send custom Python types to SQLite. But to make it +really useful we need to make the Python to SQLite to Python roundtrip work. + +Enter converters. + +Let's go back to the :class:`Point` class. We stored the x and y coordinates +separated via semicolons as strings in SQLite. + +First, we'll define a converter function that accepts the string as a parameter +and constructs a :class:`Point` object from it. + +.. note:: + +   Converter functions **always** get called with a string, no matter under which +   data type you sent the value to SQLite. + +:: + +   def convert_point(s): +       x, y = map(float, s.split(";")) +       return Point(x, y) + +Now you need to make the :mod:`sqlite3` module know that what you select from +the database is actually a point. There are two ways of doing this: + +* Implicitly via the declared type + +* Explicitly via the column name + +Both ways are described in section :ref:`sqlite3-module-contents`, in the entries +for the constants :const:`PARSE_DECLTYPES` and :const:`PARSE_COLNAMES`. + +The following example illustrates both approaches. + +.. literalinclude:: ../includes/sqlite3/converter_point.py + + +Default adapters and converters +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +There are default adapters for the date and datetime types in the datetime +module. They will be sent as ISO dates/ISO timestamps to SQLite. + +The default converters are registered under the name "date" for +:class:`datetime.date` and under the name "timestamp" for +:class:`datetime.datetime`. + +This way, you can use date/timestamps from Python without any additional +fiddling in most cases. The format of the adapters is also compatible with the +experimental SQLite date/time functions. + +The following example demonstrates this. + +.. literalinclude:: ../includes/sqlite3/pysqlite_datetime.py + + +.. _sqlite3-controlling-transactions: + +Controlling Transactions +------------------------ + +By default, the :mod:`sqlite3` module opens transactions implicitly before a +Data Modification Language (DML)  statement (i.e. +``INSERT``/``UPDATE``/``DELETE``/``REPLACE``), and commits transactions +implicitly before a non-DML, non-query statement (i. e. +anything other than ``SELECT`` or the aforementioned). + +So if you are within a transaction and issue a command like ``CREATE TABLE +...``, ``VACUUM``, ``PRAGMA``, the :mod:`sqlite3` module will commit implicitly +before executing that command. There are two reasons for doing that. The first +is that some of these commands don't work within transactions. The other reason +is that pysqlite needs to keep track of the transaction state (if a transaction +is active or not). + +You can control which kind of ``BEGIN`` statements sqlite3 implicitly executes +(or none at all) via the *isolation_level* parameter to the :func:`connect` +call, or via the :attr:`isolation_level` property of connections. + +If you want **autocommit mode**, then set :attr:`isolation_level` to None. + +Otherwise leave it at its default, which will result in a plain "BEGIN" +statement, or set it to one of SQLite's supported isolation levels: "DEFERRED", +"IMMEDIATE" or "EXCLUSIVE". + + + +Using :mod:`sqlite3` efficiently +-------------------------------- + + +Using shortcut methods +^^^^^^^^^^^^^^^^^^^^^^ + +Using the nonstandard :meth:`execute`, :meth:`executemany` and +:meth:`executescript` methods of the :class:`Connection` object, your code can +be written more concisely because you don't have to create the (often +superfluous) :class:`Cursor` objects explicitly. Instead, the :class:`Cursor` +objects are created implicitly and these shortcut methods return the cursor +objects. This way, you can execute a ``SELECT`` statement and iterate over it +directly using only a single call on the :class:`Connection` object. + +.. literalinclude:: ../includes/sqlite3/shortcut_methods.py + + +Accessing columns by name instead of by index +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +One useful feature of the :mod:`sqlite3` module is the built-in +:class:`sqlite3.Row` class designed to be used as a row factory. + +Rows wrapped with this class can be accessed both by index (like tuples) and +case-insensitively by name: + +.. literalinclude:: ../includes/sqlite3/rowclass.py + + +Using the connection as a context manager +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +With Python 2.5 or higher, connection objects can be used as context managers +that automatically commit or rollback transactions.  In the event of an +exception, the transaction is rolled back; otherwise, the transaction is +committed: + +.. literalinclude:: ../includes/sqlite3/ctx_manager.py + + +Common issues +------------- + +Multithreading +^^^^^^^^^^^^^^ + +Older SQLite versions had issues with sharing connections between threads. +That's why the Python module disallows sharing connections and cursors between +threads. If you still try to do so, you will get an exception at runtime. + +The only exception is calling the :meth:`~Connection.interrupt` method, which +only makes sense to call from a different thread. +  | 
