"sqlite3" --- DB-API 2.0 interface for SQLite databases
*******************************************************

**Code source :** Lib/sqlite3/

SQLite est une bibliothèque C qui fournit une base de données légère
sur disque ne nécessitant pas de processus serveur et qui utilise une
variante (non standard) du langage de requête SQL pour accéder aux
données. Certaines applications peuvent utiliser SQLite pour le
stockage de données internes. Il est également possible de créer une
application prototype utilisant SQLite, puis de modifier le code pour
utiliser une base de données plus robuste telle que PostgreSQL ou
Oracle.

The "sqlite3" module was written by Gerhard Häring.  It provides an
SQL interface compliant with the DB-API 2.0 specification described by
**PEP 249**, and requires SQLite 3.15.2 or newer.

Ce document inclus 4 sections principales :

* tutoriel sqlite3 explique comment utiliser le module "sqlite3".

* référence sqlite3 décrit les classes et les fonctions que ce module
  définit.

* guide sqlite3 détaille comment gérer des tâches spécifiques.

* explications sqlite3 propose un contexte détaillé du contrôle de
  transaction.

Voir aussi:

  https://www.sqlite.org
     Dans la page Web de SQLite, la documentation décrit la syntaxe et
     les types de données disponibles qui sont pris en charge par
     cette variante SQL.

  https://www.w3schools.com/sql/
     Tutoriel, référence et exemples pour apprendre la syntaxe SQL.

  **PEP 249** — Spécifications de l'API 2.0 pour la base de données
     PEP écrite par Marc-André Lemburg.


Tutoriel
========

Dans ce tutoriel, vous allez créer une base de données des films des
Monty Python en utilisant les fonctionnalités de base de "sqlite3".
Cela nécessite une compréhension élémentaire des concepts des bases de
données, notamment les curseurs et les transactions.

Tout d’abord, nous devons créer une nouvelle base de données et ouvrir
une connexion à la base de données pour permettre à "sqlite3" de
travailler avec elle. Appelez "sqlite3.connect()" pour créer une
connexion à la base de données "tutorial.db" dans le répertoire de
travail actuel, en la créant implicitement si elle n’existe pas :

   import sqlite3
   con = sqlite3.connect("tutorial.db")

L’objet "Connection" renvoyé — "con" — représente la connexion à la
base de données sur disque.

Afin d’exécuter les instructions SQL et de récupérer les résultats des
requêtes SQL, nous devrons utiliser un curseur de base de données.
Appelez "con.cursor()" pour créer la "Cursor" :

   cur = con.cursor()

Maintenant que nous avons une connexion à la base de données et un
curseur, nous pouvons créer une table "movie" avec des colonnes pour
le titre, l’année de sortie et la note de la critique. Pour plus de
simplicité, nous pouvons simplement utiliser les noms des colonnes
dans la déclaration de la table — grâce à la fonctionnalité de typage
flexible de SQLite, spécifier les types de données est facultatif.
Exécutez l’instruction "CREATE TABLE" en appelant "cur.execute(…)" :

   cur.execute("CREATE TABLE movie(title, year, score)")

Nous pouvons vérifier que la nouvelle table a été créée en
interrogeant la table "sqlite_master" intégrée à SQLite, qui devrait
maintenant contenir une entrée pour la définition de la table "movie"
(voir le schéma Table pour plus de détails). Exécutez cette requête en
appelant "cur.execute(…)", affectez le résultat à "res", et appelez
"res.fetchone()" pour récupérer la ligne résultante :

   >>> res = cur.execute("SELECT name FROM sqlite_master")
   >>> res.fetchone()
   ('movie',)

We can see that the table has been created, as the query returns a
"tuple" containing the table's name. If we query "sqlite_master" for a
non-existent table "spam", "res.fetchone()" will return "None":

   >>> res = cur.execute("SELECT name FROM sqlite_master WHERE name='spam'")
   >>> res.fetchone() is None
   True

Maintenant, ajoutez deux lignes de données en tant que littéraux SQL
en exécutant une instruction "INSERT", une fois encore en appelant
"cur.execute(…)" :

   cur.execute("""
       INSERT INTO movie VALUES
           ('Monty Python and the Holy Grail', 1975, 8.2),
           ('And Now for Something Completely Different', 1971, 7.5)
   """)

L’instruction "INSERT" ouvre implicitement une transaction, qui doit
être validée avant que les modifications ne soient enregistrées dans
la base de données (voir contrôle des transactions SQL pour plus de
détails). Appelez "con.commit()" sur l’objet de connexion pour valider
la transaction :

   con.commit()

Nous pouvons vérifier que les données ont été insérées correctement en
exécutant une requête "SELECT". Utilisez la désormais familière
"cur.execute(…)" pour affecter le résultat à "res", et appelez
"res.fetchall()" pour retourner toutes les lignes résultantes :

   >>> res = cur.execute("SELECT score FROM movie")
   >>> res.fetchall()
   [(8.2,), (7.5,)]

Le résultat est une "liste" de deux "tuple"s, une par ligne, chacun
contenant la valeur "score" de cette ligne.

Maintenant, insérez trois lignes supplémentaires en appelant
"cur.executemany(…)" :

   data = [
       ("Monty Python Live at the Hollywood Bowl", 1982, 7.9),
       ("Monty Python's The Meaning of Life", 1983, 7.5),
       ("Monty Python's Life of Brian", 1979, 8.0),
   ]
   cur.executemany("INSERT INTO movie VALUES(?, ?, ?)", data)
   con.commit()  # Remember to commit the transaction after executing INSERT.

Remarquez que les marqueurs "?" sont utilisés pour lier les "data" à
la requête. Utilisez toujours les marqueurs au lieu d’expressions
formatées pour lier les valeurs Python aux instructions SQL, afin
d’éviter les injections SQL (voir placeholder SQL pour plus de
détails).

Nous pouvons vérifier que les nouvelles lignes ont été insérées en
exécutant une requête "SELECT", cette fois-ci en itérant sur les
résultats de la requête :

   >>> for row in cur.execute("SELECT year, title FROM movie ORDER BY year"):
   ...     print(row)
   (1971, 'And Now for Something Completely Different')
   (1975, 'Monty Python and the Holy Grail')
   (1979, "Monty Python's Life of Brian")
   (1982, 'Monty Python Live at the Hollywood Bowl')
   (1983, "Monty Python's The Meaning of Life")

Chaque ligne est un "tuple" de deux éléments "(année, titre)",
correspondant aux colonnes sélectionnées dans la requête.

Enfin, vérifiez que la base de données a été écrite sur le disque en
appelant "con.close()" pour fermer la connexion existante, en ouvrir
une nouvelle, créer un nouveau curseur, puis interroger la base de
données :

   >>> con.close()
   >>> new_con = sqlite3.connect("tutorial.db")
   >>> new_cur = new_con.cursor()
   >>> res = new_cur.execute("SELECT title, year FROM movie ORDER BY score DESC")
   >>> title, year = res.fetchone()
   >>> print(f'The highest scoring Monty Python movie is {title!r}, released in {year}')
   The highest scoring Monty Python movie is 'Monty Python and the Holy Grail', released in 1975
   >>> new_con.close()

Vous avez maintenant créé une base de données SQLite à l’aide du
module "sqlite3", inséré des données et récupéré des valeurs de
plusieurs façons.

Voir aussi:

  * guide sqlite3 pour une lecture plus poussée :

    * placeholders sqlite3

    * adaptateurs sqlite3

    * convertisseurs sqlite3

    * gestionnaire de contexte de connexion sqlite3

    * guide de fabrique de ligne sqlite3

  * explications sqlite3 pour un contexte détaillé du contrôle de
    transaction.


Références
==========


Fonctions du module
-------------------

sqlite3.connect(database, timeout=5.0, detect_types=0, isolation_level='DEFERRED', check_same_thread=True, factory=sqlite3.Connection, cached_statements=128, uri=False, *, autocommit=sqlite3.LEGACY_TRANSACTION_CONTROL)

   Ouvrez une connexion à une base de données SQLite.

   Paramètres:
      * **database** (*path-like object*) -- Le chemin d’accès au
        fichier de la base de données à ouvrir. Passez "":memory :""
        pour créer une base de données SQLite existant uniquement en
        mémoire, et ouvrir une connexion à celle-ci.

      * **timeout** (*float*) -- Le temps (en secondes) que la
        connexion doit attendre avant de lever une "OperationalError",
        si la table est verrouillée. Si une autre connexion ouvre une
        transaction pour modifier la table, celle-ci sera verrouillée
        jusqu’à ce que cette transaction soit validée. Par défaut,
        cinq secondes.

      * **detect_types** (*int*) -- Control whether and how data types
        not natively supported by SQLite are looked up to be converted
        to Python types, using the converters registered with
        "register_converter()". Set it to any combination (using "|",
        bitwise or) of "PARSE_DECLTYPES" and "PARSE_COLNAMES" to
        enable this. Column names takes precedence over declared types
        if both flags are set. By default ("0"), type detection is
        disabled.

      * **isolation_level** (*str** | **None*) -- Control legacy
        transaction handling behaviour. See
        "Connection.isolation_level" and Transaction control via the
        isolation_level attribute for more information. Can be
        ""DEFERRED"" (default), ""EXCLUSIVE"" or ""IMMEDIATE""; or
        "None" to disable opening transactions implicitly. Has no
        effect unless "Connection.autocommit" is set to
        "LEGACY_TRANSACTION_CONTROL" (the default).

      * **check_same_thread** (*bool*) -- Si "True" (par défaut),
        "ProgrammingError" sera levée si la connexion à la base de
        données est utilisée par un thread autre que celui qui l’a
        créée. Si "False", la connexion peut être utilisée par
        plusieurs threads ; les opérations d’écriture devront peut-
        être être sérialisées par l’utilisateur pour éviter la
        corruption des données. Voir "sécurité des threads" pour plus
        d’informations.

      * **factory** (*Connection*) -- Une sous-classe personnalisée de
        "Connection" pour créer la connexion, si ce n’est pas la
        classe par défaut "Connection".

      * **cached_statements** (*int*) -- Le nombre d’instructions que
        "sqlite3" doit mettre en cache en interne pour cette
        connexion, afin d’éviter les surcharges d’analyse. Par défaut,
        128 instructions.

      * **uri** (*bool*) -- Si elle a pour valeur "True", la base de
        données est interprétée comme un URI (Uniform Resource
        Identifier) avec un chemin d’accès au fichier et une chaîne de
        requête facultative. La partie schéma *doit* être ""file:"",
        et le chemin peut être relatif ou absolu. La chaîne
        d’interrogation permet de passer des paramètres à SQLite, ce
        qui permet d’activer diverses astuces d’URI sqlite3.

      * **autocommit** (*bool*) -- Control **PEP 249** transaction
        handling behaviour. See "Connection.autocommit" and
        Transaction control via the autocommit attribute for more
        information. *autocommit* currently defaults to
        "LEGACY_TRANSACTION_CONTROL". The default will change to
        "False" in a future Python release.

   Type renvoyé:
      *Connection*

   Raises an auditing event "sqlite3.connect" with argument
   "database".

   Raises an auditing event "sqlite3.connect/handle" with argument
   "connection_handle".

   Modifié dans la version 3.4: Added the *uri* parameter.

   Modifié dans la version 3.7: *database* peut maintenant aussi être
   un *objet de type chemin*, et pas seulement une chaîne de
   caractères.

   Modifié dans la version 3.10: Added the "sqlite3.connect/handle"
   auditing event.

   Modifié dans la version 3.12: Added the *autocommit* parameter.

   Modifié dans la version 3.13: Positional use of the parameters
   *timeout*, *detect_types*, *isolation_level*, *check_same_thread*,
   *factory*, *cached_statements*, and *uri* is deprecated. They will
   become keyword-only parameters in Python 3.15.

sqlite3.complete_statement(statement)

   Renvoie "True" si la déclaration de la chaîne semble contenir une
   ou plusieurs déclarations SQL complètes. Aucune vérification
   syntaxique ou analyse syntaxique d’aucune sorte n’est effectuée, si
   ce n’est la vérification qu’il n’y a pas de chaîne littérale non
   fermée et que l’instruction se termine par un point-virgule.

   Exemple :

      >>> sqlite3.complete_statement("SELECT foo FROM bar;")
      True
      >>> sqlite3.complete_statement("SELECT foo")
      False

   Cette fonction peut être utile pendant la saisie en ligne de
   commande pour déterminer si le texte saisi semble former une
   instruction SQL complète, ou si une saisie supplémentaire est
   nécessaire avant d’appeler "execute()".

   See "runsource()" in Lib/sqlite3/__main__.py for real-world use.

sqlite3.enable_callback_tracebacks(flag, /)

   Activer ou désactiver les traces des fonctions de rappel. Par
   défaut, vous n’obtiendrez pas de traces de pile d’appels dans les
   fonctions définies par l’utilisateur, les agrégats, les
   convertisseurs, les fonctions de rappel des mécanismes
   d’autorisation, etc. Si vous voulez les déboguer, vous pouvez
   appeler cette fonction avec *flag* à "True". Ensuite, vous
   obtiendrez les traces des fonctions de rappel sur "sys.stderr".
   Utilisez "False" pour désactiver à nouveau cette fonctionnalité.

   Note:

     Errors in user-defined function callbacks are logged as
     unraisable exceptions. Use an "unraisable hook handler" for
     introspection of the failed callback.

sqlite3.register_adapter(type, adapter, /)

   Enregistre un *adaptateur* *callable* pour adapter le type Python
   *type* en un type SQLite. L'adaptateur est appelé avec un objet
   Python de type *type* comme seul argument, et doit retourner une
   valeur d'un type que SQLite comprend nativement.

sqlite3.register_converter(typename, converter, /)

   Enregistrer le *convertisseur* *callable* pour convertir les objets
   SQLite de type *typename* en un objet Python d'un type spécifique.
   Le convertisseur est invoqué pour toutes les valeurs SQLite de type
   *typename* ; on lui passe un objet "bytes" et il doit retourner un
   objet du type Python désiré. Consultez le paramètre *detect_types*
   de "connect()" pour plus d'informations sur le fonctionnement de la
   détection de type.

   Remarque : *typename* et le nom du type dans votre requête sont
   comparés sans tenir compte de la casse.


Fonctions et constantes du module
---------------------------------

sqlite3.LEGACY_TRANSACTION_CONTROL

   Set "autocommit" to this constant to select old style (pre-Python
   3.12) transaction control behaviour. See Transaction control via
   the isolation_level attribute for more information.

sqlite3.PARSE_DECLTYPES

   Pass this flag value to the *detect_types* parameter of "connect()"
   to look up a converter function using the declared types for each
   column. The types are declared when the database table is created.
   "sqlite3" will look up a converter function using the first word of
   the declared type as the converter dictionary key. For example:

      CREATE TABLE test(
         i integer primary key,  ! will look up a converter named "integer"
         p point,                ! will look up a converter named "point"
         n number(10)            ! will look up a converter named "number"
       )

   This flag may be combined with "PARSE_COLNAMES" using the "|"
   (bitwise or) operator.

   Note:

     Generated fields (for example "MAX(p)") are returned as "str".
     Use "PARSE_COLNAMES" to enforce types for such queries.

sqlite3.PARSE_COLNAMES

   Pass this flag value to the *detect_types* parameter of "connect()"
   to look up a converter function by using the type name, parsed from
   the query column name, as the converter dictionary key. The query
   column name must be wrapped in double quotes (""") and the type
   name must be wrapped in square brackets ("[]").

      SELECT MAX(p) as "p [point]" FROM test;  ! will look up converter "point"

   This flag may be combined with "PARSE_DECLTYPES" using the "|"
   (bitwise or) operator.

sqlite3.SQLITE_OK
sqlite3.SQLITE_DENY
sqlite3.SQLITE_IGNORE

   Flags that should be returned by the *authorizer_callback*
   *callable* passed to "Connection.set_authorizer()", to indicate
   whether:

   * Access is allowed ("SQLITE_OK"),

   * The SQL statement should be aborted with an error ("SQLITE_DENY")

   * The column should be treated as a "NULL" value ("SQLITE_IGNORE")

sqlite3.apilevel

   String constant stating the supported DB-API level. Required by the
   DB-API. Hard-coded to ""2.0"".

sqlite3.paramstyle

   String constant stating the type of parameter marker formatting
   expected by the "sqlite3" module. Required by the DB-API. Hard-
   coded to ""qmark"".

   Note:

     The "named" DB-API parameter style is also supported.

sqlite3.sqlite_version

   Version number of the runtime SQLite library as a "string".

sqlite3.sqlite_version_info

   Version number of the runtime SQLite library as a "tuple" of
   "integers".

sqlite3.threadsafety

   Integer constant required by the DB-API 2.0, stating the level of
   thread safety the "sqlite3" module supports. This attribute is set
   based on the default threading mode the underlying SQLite library
   is compiled with. The SQLite threading modes are:

   1. **Single-thread**: In this mode, all mutexes are disabled and
      SQLite is unsafe to use in more than a single thread at once.

   2. **Multi-thread**: In this mode, SQLite can be safely used by
      multiple threads provided that no single database connection is
      used simultaneously in two or more threads.

   3. **Serialized**: In serialized mode, SQLite can be safely used by
      multiple threads with no restriction.

   The mappings from SQLite threading modes to DB-API 2.0 threadsafety
   levels are as follows:

   +--------------------+------------------------+------------------------+---------------------------------+
   | SQLite threading   | **threadsafety**       | SQLITE_THREADSAFE      | DB-API 2.0 meaning              |
   | mode               |                        |                        |                                 |
   |====================|========================|========================|=================================|
   | single-thread      | 0                      | 0                      | Threads may not share the       |
   |                    |                        |                        | module                          |
   +--------------------+------------------------+------------------------+---------------------------------+
   | multi-thread       | 1                      | 2                      | Threads may share the module,   |
   |                    |                        |                        | but not connections             |
   +--------------------+------------------------+------------------------+---------------------------------+
   | serialized         | 3                      | 1                      | Threads may share the module,   |
   |                    |                        |                        | connections and cursors         |
   +--------------------+------------------------+------------------------+---------------------------------+

   Modifié dans la version 3.11: Set *threadsafety* dynamically
   instead of hard-coding it to "1".

sqlite3.version

   Version number of this module as a "string". This is not the
   version of the SQLite library.

   Deprecated since version 3.12, will be removed in version 3.14:
   This constant used to reflect the version number of the "pysqlite"
   package, a third-party library which used to upstream changes to
   "sqlite3". Today, it carries no meaning or practical value.

sqlite3.version_info

   Version number of this module as a "tuple" of "integers". This is
   not the version of the SQLite library.

   Deprecated since version 3.12, will be removed in version 3.14:
   This constant used to reflect the version number of the "pysqlite"
   package, a third-party library which used to upstream changes to
   "sqlite3". Today, it carries no meaning or practical value.

sqlite3.SQLITE_DBCONFIG_DEFENSIVE
sqlite3.SQLITE_DBCONFIG_DQS_DDL
sqlite3.SQLITE_DBCONFIG_DQS_DML
sqlite3.SQLITE_DBCONFIG_ENABLE_FKEY
sqlite3.SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER
sqlite3.SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION
sqlite3.SQLITE_DBCONFIG_ENABLE_QPSG
sqlite3.SQLITE_DBCONFIG_ENABLE_TRIGGER
sqlite3.SQLITE_DBCONFIG_ENABLE_VIEW
sqlite3.SQLITE_DBCONFIG_LEGACY_ALTER_TABLE
sqlite3.SQLITE_DBCONFIG_LEGACY_FILE_FORMAT
sqlite3.SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE
sqlite3.SQLITE_DBCONFIG_RESET_DATABASE
sqlite3.SQLITE_DBCONFIG_TRIGGER_EQP
sqlite3.SQLITE_DBCONFIG_TRUSTED_SCHEMA
sqlite3.SQLITE_DBCONFIG_WRITABLE_SCHEMA

   These constants are used for the "Connection.setconfig()" and
   "getconfig()" methods.

   The availability of these constants varies depending on the version
   of SQLite Python was compiled with.

   Ajouté dans la version 3.12.

   Voir aussi:

     https://www.sqlite.org/c3ref/c_dbconfig_defensive.html
        SQLite docs: Database Connection Configuration Options


Connection objects
------------------

class sqlite3.Connection

   Each open SQLite database is represented by a "Connection" object,
   which is created using "sqlite3.connect()". Their main purpose is
   creating "Cursor" objects, and Transaction control.

   Voir aussi:

     * How to use connection shortcut methods

     * gestionnaire de contexte de connexion sqlite3

   Modifié dans la version 3.13: A "ResourceWarning" is emitted if
   "close()" is not called before a "Connection" object is deleted.

   An SQLite database connection has the following attributes and
   methods:

   cursor(factory=Cursor)

      Create and return a "Cursor" object. The cursor method accepts a
      single optional parameter *factory*. If supplied, this must be a
      *callable* returning an instance of "Cursor" or its subclasses.

   blobopen(table, column, row, /, *, readonly=False, name='main')

      Open a "Blob" handle to an existing BLOB (Binary Large OBject).

      Paramètres:
         * **table** (*str*) -- The name of the table where the blob
           is located.

         * **column** (*str*) -- The name of the column where the blob
           is located.

         * **row** (*str*) -- The name of the row where the blob is
           located.

         * **readonly** (*bool*) -- Set to "True" if the blob should
           be opened without write permissions. Defaults to "False".

         * **name** (*str*) -- The name of the database where the blob
           is located. Defaults to ""main"".

      Lève:
         **OperationalError** -- When trying to open a blob in a
         "WITHOUT ROWID" table.

      Type renvoyé:
         Blob

      Note:

        The blob size cannot be changed using the "Blob" class. Use
        the SQL function "zeroblob" to create a blob with a fixed
        size.

      Ajouté dans la version 3.11.

   commit()

      Commit any pending transaction to the database. If "autocommit"
      is "True", or there is no open transaction, this method does
      nothing. If "autocommit" is "False", a new transaction is
      implicitly opened if a pending transaction was committed by this
      method.

   rollback()

      Roll back to the start of any pending transaction. If
      "autocommit" is "True", or there is no open transaction, this
      method does nothing. If "autocommit" is "False", a new
      transaction is implicitly opened if a pending transaction was
      rolled back by this method.

   close()

      Close the database connection. If "autocommit" is "False", any
      pending transaction is implicitly rolled back. If "autocommit"
      is "True" or "LEGACY_TRANSACTION_CONTROL", no implicit
      transaction control is executed. Make sure to "commit()" before
      closing to avoid losing pending changes.

   execute(sql, parameters=(), /)

      Create a new "Cursor" object and call "execute()" on it with the
      given *sql* and *parameters*. Return the new cursor object.

   executemany(sql, parameters, /)

      Create a new "Cursor" object and call "executemany()" on it with
      the given *sql* and *parameters*. Return the new cursor object.

   executescript(sql_script, /)

      Create a new "Cursor" object and call "executescript()" on it
      with the given *sql_script*. Return the new cursor object.

   create_function(name, narg, func, *, deterministic=False)

      Create or remove a user-defined SQL function.

      Paramètres:
         * **name** (*str*) -- The name of the SQL function.

         * **narg** (*int*) -- The number of arguments the SQL
           function can accept. If "-1", it may take any number of
           arguments.

         * **func** (*callback* | None) -- A *callable* that is called
           when the SQL function is invoked. The callable must return
           a type natively supported by SQLite. Set to "None" to
           remove an existing SQL function.

         * **deterministic** (*bool*) -- If "True", the created SQL
           function is marked as deterministic, which allows SQLite to
           perform additional optimizations.

      Modifié dans la version 3.8: Added the *deterministic*
      parameter.

      Exemple :

         >>> import hashlib
         >>> def md5sum(t):
         ...     return hashlib.md5(t).hexdigest()
         >>> con = sqlite3.connect(":memory:")
         >>> con.create_function("md5", 1, md5sum)
         >>> for row in con.execute("SELECT md5(?)", (b"foo",)):
         ...     print(row)
         ('acbd18db4cc2f85cedef654fccc4a4d8',)
         >>> con.close()

      Modifié dans la version 3.13: Passing *name*, *narg*, and *func*
      as keyword arguments is deprecated. These parameters will become
      positional-only in Python 3.15.

   create_aggregate(name, n_arg, aggregate_class)

      Create or remove a user-defined SQL aggregate function.

      Paramètres:
         * **name** (*str*) -- The name of the SQL aggregate function.

         * **n_arg** (*int*) -- The number of arguments the SQL
           aggregate function can accept. If "-1", it may take any
           number of arguments.

         * **aggregate_class** (*class* | None) --

           A class must implement the following methods:

           * "step()": Add a row to the aggregate.

           * "finalize()": Return the final result of the aggregate as
             a type natively supported by SQLite.

           The number of arguments that the "step()" method must
           accept is controlled by *n_arg*.

           Set to "None" to remove an existing SQL aggregate function.

      Exemple :

         class MySum:
             def __init__(self):
                 self.count = 0

             def step(self, value):
                 self.count += value

             def finalize(self):
                 return self.count

         con = sqlite3.connect(":memory:")
         con.create_aggregate("mysum", 1, MySum)
         cur = con.execute("CREATE TABLE test(i)")
         cur.execute("INSERT INTO test(i) VALUES(1)")
         cur.execute("INSERT INTO test(i) VALUES(2)")
         cur.execute("SELECT mysum(i) FROM test")
         print(cur.fetchone()[0])

         con.close()

      Modifié dans la version 3.13: Passing *name*, *n_arg*, and
      *aggregate_class* as keyword arguments is deprecated. These
      parameters will become positional-only in Python 3.15.

   create_window_function(name, num_params, aggregate_class, /)

      Create or remove a user-defined aggregate window function.

      Paramètres:
         * **name** (*str*) -- The name of the SQL aggregate window
           function to create or remove.

         * **num_params** (*int*) -- The number of arguments the SQL
           aggregate window function can accept. If "-1", it may take
           any number of arguments.

         * **aggregate_class** (*class* | None) --

           A class that 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
             a type natively supported by SQLite.

           The number of arguments that the "step()" and "value()"
           methods must accept is controlled by *num_params*.

           Set to "None" to remove an existing SQL aggregate window
           function.

      Lève:
         **NotSupportedError** -- If used with a version of SQLite
         older than 3.25.0, which does not support aggregate window
         functions.

      Ajouté dans la version 3.11.

      Exemple :

         # Example taken from https://www.sqlite.org/windowfunctions.html#udfwinfunc
         class WindowSumInt:
             def __init__(self):
                 self.count = 0

             def step(self, value):
                 """Add a row to the current window."""
                 self.count += value

             def value(self):
                 """Return the current value of the aggregate."""
                 return self.count

             def inverse(self, value):
                 """Remove a row from the current window."""
                 self.count -= value

             def finalize(self):
                 """Return the final value of the aggregate.

                 Any clean-up actions should be placed here.
                 """
                 return self.count


         con = sqlite3.connect(":memory:")
         cur = con.execute("CREATE TABLE test(x, y)")
         values = [
             ("a", 4),
             ("b", 5),
             ("c", 3),
             ("d", 8),
             ("e", 1),
         ]
         cur.executemany("INSERT INTO test VALUES(?, ?)", values)
         con.create_window_function("sumint", 1, WindowSumInt)
         cur.execute("""
             SELECT x, sumint(y) OVER (
                 ORDER BY x ROWS BETWEEN 1 PRECEDING AND 1 FOLLOWING
             ) AS sum_y
             FROM test ORDER BY x
         """)
         print(cur.fetchall())
         con.close()

   create_collation(name, callable, /)

      Create a collation named *name* using the collating function
      *callable*. *callable* is passed two "string" arguments, and it
      should return an "integer":

      * "1" if the first is ordered higher than the second

      * "-1" if the first is ordered lower than the second

      * "0" if they are ordered equal

      The following example shows a reverse sorting collation:

         def collate_reverse(string1, string2):
             if string1 == string2:
                 return 0
             elif string1 < string2:
                 return 1
             else:
                 return -1

         con = sqlite3.connect(":memory:")
         con.create_collation("reverse", collate_reverse)

         cur = con.execute("CREATE TABLE test(x)")
         cur.executemany("INSERT INTO test(x) VALUES(?)", [("a",), ("b",)])
         cur.execute("SELECT x FROM test ORDER BY x COLLATE reverse")
         for row in cur:
             print(row)
         con.close()

      Remove a collation function by setting *callable* to "None".

      Modifié dans la version 3.11: The collation name can contain any
      Unicode character.  Earlier, only ASCII characters were allowed.

   interrupt()

      Call this method from a different thread to abort any queries
      that might be executing on the connection. Aborted queries will
      raise an "OperationalError".

   set_authorizer(authorizer_callback)

      Register *callable* *authorizer_callback* to be invoked for each
      attempt to access a column of a table in the database. The
      callback should return one of "SQLITE_OK", "SQLITE_DENY", or
      "SQLITE_IGNORE" to signal how access to the column should be
      handled by the underlying SQLite library.

      The first argument to the callback signifies what kind of
      operation is to be authorized. The second and third argument
      will be arguments or "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
      "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 "sqlite3" module.

      Passing "None" as *authorizer_callback* will disable the
      authorizer.

      Modifié dans la version 3.11: Added support for disabling the
      authorizer using "None".

      Modifié dans la version 3.13: Passing *authorizer_callback* as a
      keyword argument is deprecated. The parameter will become
      positional-only in Python 3.15.

   set_progress_handler(progress_handler, n)

      Register *callable* *progress_handler* to be 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 "None" for *progress_handler*.

      Returning a non-zero value from the handler function will
      terminate the currently executing query and cause it to raise a
      "DatabaseError" exception.

      Modifié dans la version 3.13: Passing *progress_handler* as a
      keyword argument is deprecated. The parameter will become
      positional-only in Python 3.15.

   set_trace_callback(trace_callback)

      Register *callable* *trace_callback* to be invoked for each SQL
      statement that is actually executed by the SQLite backend.

      The only argument passed to the callback is the statement (as
      "str") that is being executed. The return value of the callback
      is ignored. Note that the backend does not only run statements
      passed to the "Cursor.execute()" methods.  Other sources include
      the transaction management of the "sqlite3" module and the
      execution of triggers defined in the current database.

      Passing "None" as *trace_callback* will disable the trace
      callback.

      Note:

        Exceptions raised in the trace callback are not propagated. As
        a development and debugging aid, use
        "enable_callback_tracebacks()" to enable printing tracebacks
        from exceptions raised in the trace callback.

      Ajouté dans la version 3.3.

      Modifié dans la version 3.13: Passing *trace_callback* as a
      keyword argument is deprecated. The parameter will become
      positional-only in Python 3.15.

   enable_load_extension(enabled, /)

      Enable the SQLite engine to load SQLite extensions from shared
      libraries if *enabled* is "True"; else, disallow loading SQLite
      extensions. 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.

      Note:

        The "sqlite3" module is not built with loadable extension
        support by default, because some platforms (notably macOS)
        have SQLite libraries which are compiled without this feature.
        To get loadable extension support, you must pass the "--
        enable-loadable-sqlite-extensions" option to **configure**.

      Raises an auditing event "sqlite3.enable_load_extension" with
      arguments "connection", "enabled".

      Ajouté dans la version 3.2.

      Modifié dans la version 3.10: Added the
      "sqlite3.enable_load_extension" auditing event.

         con.enable_load_extension(True)

         # Load the fulltext search extension
         con.execute("select load_extension('./fts3.so')")

         # alternatively you can load the extension using an API call:
         # con.load_extension("./fts3.so")

         # disable extension loading again
         con.enable_load_extension(False)

         # example from SQLite wiki
         con.execute("CREATE VIRTUAL TABLE recipe USING fts3(name, ingredients)")
         con.executescript("""
             INSERT INTO recipe (name, ingredients) VALUES('broccoli stew', 'broccoli peppers cheese tomatoes');
             INSERT INTO recipe (name, ingredients) VALUES('pumpkin stew', 'pumpkin onions garlic celery');
             INSERT INTO recipe (name, ingredients) VALUES('broccoli pie', 'broccoli cheese onions flour');
             INSERT INTO recipe (name, ingredients) VALUES('pumpkin pie', 'pumpkin sugar flour butter');
             """)
         for row in con.execute("SELECT rowid, name, ingredients FROM recipe WHERE name MATCH 'pie'"):
             print(row)

   load_extension(path, /, *, entrypoint=None)

      Load an SQLite extension from a shared library. Enable extension
      loading with "enable_load_extension()" before calling this
      method.

      Paramètres:
         * **path** (*str*) -- The path to the SQLite extension.

         * **entrypoint** (*str** | **None*) -- Entry point name. If
           "None" (the default), SQLite will come up with an entry
           point name of its own; see the SQLite docs Loading an
           Extension for details.

      Raises an auditing event "sqlite3.load_extension" with arguments
      "connection", "path".

      Ajouté dans la version 3.2.

      Modifié dans la version 3.10: Added the "sqlite3.load_extension"
      auditing event.

      Modifié dans la version 3.12: Added the *entrypoint* parameter.

   iterdump(*, filter=None)

      Return an *iterator* to dump the database as SQL source code.
      Useful when saving an in-memory database for later restoration.
      Similar to the ".dump" command in the **sqlite3** shell.

      Paramètres:
         **filter** (*str** | **None*) -- An optional "LIKE" pattern
         for database objects to dump, e.g. "prefix_%". If "None" (the
         default), all database objects will be included.

      Exemple :

         # Convert file example.db to SQL dump file dump.sql
         con = sqlite3.connect('example.db')
         with open('dump.sql', 'w') as f:
             for line in con.iterdump():
                 f.write('%s\n' % line)
         con.close()

      Voir aussi: How to handle non-UTF-8 text encodings

      Modifié dans la version 3.13: Ajout du paramètre *filter*.

   backup(target, *, pages=-1, progress=None, name='main', sleep=0.250)

      Create a backup of an SQLite database.

      Works even if the database is being accessed by other clients or
      concurrently by the same connection.

      Paramètres:
         * **target** (*Connection*) -- The database connection to
           save the backup to.

         * **pages** (*int*) -- 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".

         * **progress** (*callback* | None) -- 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 "None".

         * **name** (*str*) -- 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
           statement.

         * **sleep** (*float*) -- The number of seconds to sleep
           between successive attempts to back up remaining pages.

      Example 1, copy an existing database into another:

         def progress(status, remaining, total):
             print(f'Copied {total-remaining} of {total} pages...')

         src = sqlite3.connect('example.db')
         dst = sqlite3.connect('backup.db')
         with dst:
             src.backup(dst, pages=1, progress=progress)
         dst.close()
         src.close()

      Example 2, copy an existing database into a transient copy:

         src = sqlite3.connect('example.db')
         dst = sqlite3.connect(':memory:')
         src.backup(dst)
         dst.close()
         src.close()

      Ajouté dans la version 3.7.

      Voir aussi: How to handle non-UTF-8 text encodings

   getlimit(category, /)

      Get a connection runtime limit.

      Paramètres:
         **category** (*int*) -- The SQLite limit category to be
         queried.

      Type renvoyé:
         int

      Lève:
         **ProgrammingError** -- If *category* is not recognised by
         the underlying SQLite library.

      Example, query the maximum length of an SQL statement for
      "Connection" "con" (the default is 1000000000):

         >>> con.getlimit(sqlite3.SQLITE_LIMIT_SQL_LENGTH)
         1000000000

      Ajouté dans la version 3.11.

   setlimit(category, limit, /)

      Set a connection runtime limit. Attempts to increase a limit
      above its hard upper bound are silently truncated to the hard
      upper bound. Regardless of whether or not the limit was changed,
      the prior value of the limit is returned.

      Paramètres:
         * **category** (*int*) -- The SQLite limit category to be
           set.

         * **limit** (*int*) -- The value of the new limit. If
           negative, the current limit is unchanged.

      Type renvoyé:
         int

      Lève:
         **ProgrammingError** -- If *category* is not recognised by
         the underlying SQLite library.

      Example, limit the number of attached databases to 1 for
      "Connection" "con" (the default limit is 10):

         >>> con.setlimit(sqlite3.SQLITE_LIMIT_ATTACHED, 1)
         10
         >>> con.getlimit(sqlite3.SQLITE_LIMIT_ATTACHED)
         1

      Ajouté dans la version 3.11.

   getconfig(op, /)

      Query a boolean connection configuration option.

      Paramètres:
         **op** (*int*) -- A SQLITE_DBCONFIG code.

      Type renvoyé:
         bool

      Ajouté dans la version 3.12.

   setconfig(op, enable=True, /)

      Set a boolean connection configuration option.

      Paramètres:
         * **op** (*int*) -- A SQLITE_DBCONFIG code.

         * **enable** (*bool*) -- "True" if the configuration option
           should be enabled (default); "False" if it should be
           disabled.

      Ajouté dans la version 3.12.

   serialize(*, name='main')

      Serialize a database into a "bytes" object.  For an ordinary on-
      disk database file, the serialization is just a copy of the disk
      file.  For an in-memory database or a "temp" database, the
      serialization is the same sequence of bytes which would be
      written to disk if that database were backed up to disk.

      Paramètres:
         **name** (*str*) -- The database name to be serialized.
         Defaults to ""main"".

      Type renvoyé:
         bytes

      Note:

        This method is only available if the underlying SQLite library
        has the serialize API.

      Ajouté dans la version 3.11.

   deserialize(data, /, *, name='main')

      Deserialize a "serialized" database into a "Connection". This
      method causes the database connection to disconnect from
      database *name*, and reopen *name* as an in-memory database
      based on the serialization contained in *data*.

      Paramètres:
         * **data** (*bytes*) -- A serialized database.

         * **name** (*str*) -- The database name to deserialize into.
           Defaults to ""main"".

      Lève:
         * **OperationalError** -- If the database connection is
           currently involved in a read transaction or a backup
           operation.

         * **DatabaseError** -- If *data* does not contain a valid
           SQLite database.

         * **OverflowError** -- If "len(data)" is larger than "2**63 -
           1".

      Note:

        This method is only available if the underlying SQLite library
        has the deserialize API.

      Ajouté dans la version 3.11.

   autocommit

      This attribute controls **PEP 249**-compliant transaction
      behaviour. "autocommit" has three allowed values:

      * "False": Select **PEP 249**-compliant transaction behaviour,
        implying that "sqlite3" ensures a transaction is always open.
        Use "commit()" and "rollback()" to close transactions.

        This is the recommended value of "autocommit".

      * "True": Use SQLite's autocommit mode. "commit()" and
        "rollback()" have no effect in this mode.

      * "LEGACY_TRANSACTION_CONTROL": Pre-Python 3.12 (non-**PEP
        249**-compliant) transaction control. See "isolation_level"
        for more details.

        This is currently the default value of "autocommit".

      Changing "autocommit" to "False" will open a new transaction,
      and changing it to "True" will commit any pending transaction.

      See Transaction control via the autocommit attribute for more
      details.

      Note:

        The "isolation_level" attribute has no effect unless
        "autocommit" is "LEGACY_TRANSACTION_CONTROL".

      Ajouté dans la version 3.12.

   in_transaction

      This read-only attribute corresponds to the low-level SQLite
      autocommit mode.

      "True" if a transaction is active (there are uncommitted
      changes), "False" otherwise.

      Ajouté dans la version 3.2.

   isolation_level

      Controls the legacy transaction handling mode of "sqlite3". If
      set to "None", transactions are never implicitly opened. If set
      to one of ""DEFERRED"", ""IMMEDIATE"", or ""EXCLUSIVE"",
      corresponding to the underlying SQLite transaction behaviour,
      implicit transaction management is performed.

      If not overridden by the *isolation_level* parameter of
      "connect()", the default is """", which is an alias for
      ""DEFERRED"".

      Note:

        Using "autocommit" to control transaction handling is
        recommended over using "isolation_level". "isolation_level"
        has no effect unless "autocommit" is set to
        "LEGACY_TRANSACTION_CONTROL" (the default).

   row_factory

      The initial "row_factory" for "Cursor" objects created from this
      connection. Assigning to this attribute does not affect the
      "row_factory" of existing cursors belonging to this connection,
      only new ones. Is "None" by default, meaning each row is
      returned as a "tuple".

      See How to create and use row factories for more details.

   text_factory

      A *callable* that accepts a "bytes" parameter and returns a text
      representation of it. The callable is invoked for SQLite values
      with the "TEXT" data type. By default, this attribute is set to
      "str".

      See How to handle non-UTF-8 text encodings for more details.

   total_changes

      Return the total number of database rows that have been
      modified, inserted, or deleted since the database connection was
      opened.


Cursor objects
--------------

   A "Cursor" object represents a database cursor which is used to
   execute SQL statements, and manage the context of a fetch
   operation. Cursors are created using "Connection.cursor()", or by
   using any of the connection shortcut methods.

   Cursor objects are *iterators*, meaning that if you "execute()" a
   "SELECT" query, you can simply iterate over the cursor to fetch the
   resulting rows:

      for row in cur.execute("SELECT t FROM data"):
          print(row)

class sqlite3.Cursor

   A "Cursor" instance has the following attributes and methods.

   execute(sql, parameters=(), /)

      Execute a single SQL statement, optionally binding Python values
      using placeholders.

      Paramètres:
         * **sql** (*str*) -- A single SQL statement.

         * **parameters** ("dict" | *sequence*) -- Python values to
           bind to placeholders in *sql*. A "dict" if named
           placeholders are used. A *sequence* if unnamed placeholders
           are used. See How to use placeholders to bind values in SQL
           queries.

      Lève:
         **ProgrammingError** -- If *sql* contains more than one SQL
         statement.

      If "autocommit" is "LEGACY_TRANSACTION_CONTROL",
      "isolation_level" is not "None", *sql* is an "INSERT", "UPDATE",
      "DELETE", or "REPLACE" statement, and there is no open
      transaction, a transaction is implicitly opened before executing
      *sql*.

      Deprecated since version 3.12, will be removed in version 3.14:
      "DeprecationWarning" is emitted if named placeholders are used
      and *parameters* is a sequence instead of a "dict". Starting
      with Python 3.14, "ProgrammingError" will be raised instead.

      Use "executescript()" to execute multiple SQL statements.

   executemany(sql, parameters, /)

      For every item in *parameters*, repeatedly execute the
      parameterized DML (Data Manipulation Language) SQL statement
      *sql*.

      Uses the same implicit transaction handling as "execute()".

      Paramètres:
         * **sql** (*str*) -- A single SQL DML statement.

         * **parameters** (*iterable*) -- An *iterable* of parameters
           to bind with the placeholders in *sql*. See How to use
           placeholders to bind values in SQL queries.

      Lève:
         **ProgrammingError** -- If *sql* contains more than one SQL
         statement, or is not a DML statement.

      Exemple :

         rows = [
             ("row1",),
             ("row2",),
         ]
         # cur is an sqlite3.Cursor object
         cur.executemany("INSERT INTO data VALUES(?)", rows)

      Note:

        Any resulting rows are discarded, including DML statements
        with RETURNING clauses.

      Deprecated since version 3.12, will be removed in version 3.14:
      "DeprecationWarning" is emitted if named placeholders are used
      and the items in *parameters* are sequences instead of "dict"s.
      Starting with Python 3.14, "ProgrammingError" will be raised
      instead.

   executescript(sql_script, /)

      Execute the SQL statements in *sql_script*. If the "autocommit"
      is "LEGACY_TRANSACTION_CONTROL" and there is a pending
      transaction, an implicit "COMMIT" statement is executed first.
      No other implicit transaction control is performed; any
      transaction control must be added to *sql_script*.

      *sql_script* must be a "string".

      Exemple :

         # cur is an sqlite3.Cursor object
         cur.executescript("""
             BEGIN;
             CREATE TABLE person(firstname, lastname, age);
             CREATE TABLE book(title, author, published);
             CREATE TABLE publisher(name, address);
             COMMIT;
         """)

   fetchone()

      If "row_factory" is "None", return the next row query result set
      as a "tuple". Else, pass it to the row factory and return its
      result. Return "None" if no more data is available.

   fetchmany(size=cursor.arraysize)

      Return the next set of rows of a query result as a "list".
      Return an empty list if no more rows are available.

      The number of rows to fetch per call is specified by the *size*
      parameter. If *size* is not given, "arraysize" determines the
      number of rows to be fetched. If fewer than *size* rows are
      available, as many rows as are available are 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
      "fetchmany()" call to the next.

   fetchall()

      Return all (remaining) rows of a query result as a "list".
      Return an empty list if no rows are available. Note that the
      "arraysize" attribute can affect the performance of this
      operation.

   close()

      Close the cursor now (rather than whenever "__del__" is called).

      The cursor will be unusable from this point forward; a
      "ProgrammingError" exception will be raised if any operation is
      attempted with the cursor.

   setinputsizes(sizes, /)

      Required by the DB-API. Does nothing in "sqlite3".

   setoutputsize(size, column=None, /)

      Required by the DB-API. Does nothing in "sqlite3".

   arraysize

      Read/write attribute that controls the number of rows returned
      by "fetchmany()". The default value is 1 which means a single
      row would be fetched per call.

   connection

      Read-only attribute that provides the SQLite database
      "Connection" belonging to the cursor.  A "Cursor" object created
      by calling "con.cursor()" will have a "connection" attribute
      that refers to *con*:

         >>> con = sqlite3.connect(":memory:")
         >>> cur = con.cursor()
         >>> cur.connection == con
         True
         >>> con.close()

   description

      Read-only attribute that 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 "None".

      It is set for "SELECT" statements without any matching rows as
      well.

   lastrowid

      Read-only attribute that provides the row id of the last
      inserted row. It is only updated after successful "INSERT" or
      "REPLACE" statements using the "execute()" method.  For other
      statements, after "executemany()" or "executescript()", or if
      the insertion failed, the value of "lastrowid" is left
      unchanged.  The initial value of "lastrowid" is "None".

      Note:

        Inserts into "WITHOUT ROWID" tables are not recorded.

      Modifié dans la version 3.6: Added support for the "REPLACE"
      statement.

   rowcount

      Read-only attribute that provides the number of modified rows
      for "INSERT", "UPDATE", "DELETE", and "REPLACE" statements; is
      "-1" for other statements, including CTE (Common Table
      Expression) queries. It is only updated by the "execute()" and
      "executemany()" methods, after the statement has run to
      completion. This means that any resulting rows must be fetched
      in order for "rowcount" to be updated.

   row_factory

      Control how a row fetched from this "Cursor" is represented. If
      "None", a row is represented as a "tuple". Can be set to the
      included "sqlite3.Row"; or a *callable* that accepts two
      arguments, a "Cursor" object and the "tuple" of row values, and
      returns a custom object representing an SQLite row.

      Defaults to what "Connection.row_factory" was set to when the
      "Cursor" was created. Assigning to this attribute does not
      affect "Connection.row_factory" of the parent connection.

      See How to create and use row factories for more details.


Row objects
-----------

class sqlite3.Row

   A "Row" instance serves as a highly optimized "row_factory" for
   "Connection" objects. It supports iteration, equality testing,
   "len()", and *mapping* access by column name and index.

   Two "Row" objects compare equal if they have identical column names
   and values.

   See How to create and use row factories for more details.

   keys()

      Return a "list" of column names as "strings". Immediately after
      a query, it is the first member of each tuple in
      "Cursor.description".

   Modifié dans la version 3.5: Added support of slicing.


Blob objects
------------

class sqlite3.Blob

   Ajouté dans la version 3.11.

   A "Blob" instance is a *file-like object* that can read and write
   data in an SQLite BLOB (Binary Large OBject). Call "len(blob)" to
   get the size (number of bytes) of the blob. Use indices and
   *slices* for direct access to the blob data.

   Use the "Blob" as a *context manager* to ensure that the blob
   handle is closed after use.

      con = sqlite3.connect(":memory:")
      con.execute("CREATE TABLE test(blob_col blob)")
      con.execute("INSERT INTO test(blob_col) VALUES(zeroblob(13))")

      # Write to our blob, using two write operations:
      with con.blobopen("test", "blob_col", 1) as blob:
          blob.write(b"hello, ")
          blob.write(b"world.")
          # Modify the first and last bytes of our blob
          blob[0] = ord("H")
          blob[-1] = ord("!")

      # Read the contents of our blob
      with con.blobopen("test", "blob_col", 1) as blob:
          greeting = blob.read()

      print(greeting)  # outputs "b'Hello, world!'"
      con.close()

   close()

      Close the blob.

      The blob will be unusable from this point onward.  An "Error"
      (or subclass) exception will be raised if any further operation
      is attempted with the blob.

   read(length=-1, /)

      Read *length* bytes of data from the blob at the current offset
      position. If the end of the blob is reached, the data up to EOF
      (End of File) will be returned.  When *length* is not specified,
      or is negative, "read()" will read until the end of the blob.

   write(data, /)

      Write *data* to the blob at the current offset.  This function
      cannot change the blob length.  Writing beyond the end of the
      blob will raise "ValueError".

   tell()

      Return the current access position of the blob.

   seek(offset, origin=os.SEEK_SET, /)

      Set the current access position of the blob to *offset*.  The
      *origin* argument defaults to "os.SEEK_SET" (absolute blob
      positioning). Other values for *origin* are "os.SEEK_CUR" (seek
      relative to the current position) and "os.SEEK_END" (seek
      relative to the blob’s end).


PrepareProtocol objects
-----------------------

class sqlite3.PrepareProtocol

   The PrepareProtocol type's single purpose is to act as a **PEP
   246** style adaption protocol for objects that can adapt themselves
   to native SQLite types.


Exceptions
----------

The exception hierarchy is defined by the DB-API 2.0 (**PEP 249**).

exception sqlite3.Warning

   This exception is not currently raised by the "sqlite3" module, but
   may be raised by applications using "sqlite3", for example if a
   user-defined function truncates data while inserting. "Warning" is
   a subclass of "Exception".

exception sqlite3.Error

   The base class of the other exceptions in this module. Use this to
   catch all errors with one single "except" statement. "Error" is a
   subclass of "Exception".

   If the exception originated from within the SQLite library, the
   following two attributes are added to the exception:

   sqlite_errorcode

      The numeric error code from the SQLite API

      Ajouté dans la version 3.11.

   sqlite_errorname

      The symbolic name of the numeric error code from the SQLite API

      Ajouté dans la version 3.11.

exception sqlite3.InterfaceError

   Exception raised for misuse of the low-level SQLite C API. In other
   words, if this exception is raised, it probably indicates a bug in
   the "sqlite3" module. "InterfaceError" is a subclass of "Error".

exception sqlite3.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 "Error".

exception sqlite3.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 "DatabaseError".

exception sqlite3.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
   "DatabaseError".

exception sqlite3.IntegrityError

   Exception raised when the relational integrity of the database is
   affected, e.g. a foreign key check fails.  It is a subclass of
   "DatabaseError".

exception sqlite3.InternalError

   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 "DatabaseError".

exception sqlite3.ProgrammingError

   Exception raised for "sqlite3" API programming errors, for example
   supplying the wrong number of bindings to a query, or trying to
   operate on a closed "Connection". "ProgrammingError" is a subclass
   of "DatabaseError".

exception sqlite3.NotSupportedError

   Exception raised in case a method or database API is not supported
   by the underlying SQLite library. For example, setting
   *deterministic* to "True" in "create_function()", if the underlying
   SQLite library does not support deterministic functions.
   "NotSupportedError" is a subclass of "DatabaseError".


SQLite and Python types
-----------------------

SQLite natively supports the following types: "NULL", "INTEGER",
"REAL", "TEXT", "BLOB".

The following Python types can thus be sent to SQLite without any
problem:

+---------------------------------+---------------+
| Type Python                     | SQLite type   |
|=================================|===============|
| "None"                          | "NULL"        |
+---------------------------------+---------------+
| "int"                           | "INTEGER"     |
+---------------------------------+---------------+
| "float"                         | "REAL"        |
+---------------------------------+---------------+
| "str"                           | "TEXT"        |
+---------------------------------+---------------+
| "bytes"                         | "BLOB"        |
+---------------------------------+---------------+

This is how SQLite types are converted to Python types by default:

+---------------+------------------------------------------------+
| SQLite type   | Type Python                                    |
|===============|================================================|
| "NULL"        | "None"                                         |
+---------------+------------------------------------------------+
| "INTEGER"     | "int"                                          |
+---------------+------------------------------------------------+
| "REAL"        | "float"                                        |
+---------------+------------------------------------------------+
| "TEXT"        | depends on "text_factory", "str" by default    |
+---------------+------------------------------------------------+
| "BLOB"        | "bytes"                                        |
+---------------+------------------------------------------------+

The type system of the "sqlite3" module is extensible in two ways: you
can store additional Python types in an SQLite database via object
adapters, and you can let the "sqlite3" module convert SQLite types to
Python types via converters.


Default adapters and converters (deprecated)
--------------------------------------------

Note:

  The default adapters and converters are deprecated as of Python
  3.12. Instead, use the Adapter and converter recipes and tailor them
  to your needs.

The deprecated default adapters and converters consist of:

* An adapter for "datetime.date" objects to "strings" in ISO 8601
  format.

* An adapter for "datetime.datetime" objects to strings in ISO 8601
  format.

* A converter for declared "date" types to "datetime.date" objects.

* A converter for declared "timestamp" types to "datetime.datetime"
  objects. Fractional parts will be truncated to 6 digits (microsecond
  precision).

Note:

  The default "timestamp" converter ignores UTC offsets in the
  database and always returns a naive "datetime.datetime" object. To
  preserve UTC offsets in timestamps, either leave converters
  disabled, or register an offset-aware converter with
  "register_converter()".

Obsolète depuis la version 3.12.


Command-line interface
----------------------

The "sqlite3" module can be invoked as a script, using the
interpreter's "-m" switch, in order to provide a simple SQLite shell.
The argument signature is as follows:

   python -m sqlite3 [-h] [-v] [filename] [sql]

Type ".quit" or CTRL-D to exit the shell.

-h, --help

   Print CLI help.

-v, --version

   Print underlying SQLite library version.

Ajouté dans la version 3.12.


How-to guides
=============


How to use placeholders to bind values in SQL queries
-----------------------------------------------------

SQL operations usually need to use values from Python variables.
However, beware of using Python's string operations to assemble
queries, as they are vulnerable to SQL injection attacks. For example,
an attacker can simply close the single quote and inject "OR TRUE" to
select all rows:

   >>> # Never do this -- insecure!
   >>> symbol = input()
   ' OR TRUE; --
   >>> sql = "SELECT * FROM stocks WHERE symbol = '%s'" % symbol
   >>> print(sql)
   SELECT * FROM stocks WHERE symbol = '' OR TRUE; --'
   >>> cur.execute(sql)

Instead, use the DB-API's parameter substitution. To insert a variable
into a query string, use a placeholder in the string, and substitute
the actual values into the query by providing them as a "tuple" of
values to the second argument of the cursor's "execute()" method.

An SQL statement may use one of two kinds of placeholders: question
marks (qmark style) or named placeholders (named style). For the qmark
style, *parameters* must be a *sequence* whose length must match the
number of placeholders, or a "ProgrammingError" is raised. For the
named style, *parameters* must be an instance of a "dict" (or a
subclass), which must contain keys for all named parameters; any extra
items are ignored. Here's an example of both styles:

   con = sqlite3.connect(":memory:")
   cur = con.execute("CREATE TABLE lang(name, first_appeared)")

   # This is the named style used with executemany():
   data = (
       {"name": "C", "year": 1972},
       {"name": "Fortran", "year": 1957},
       {"name": "Python", "year": 1991},
       {"name": "Go", "year": 2009},
   )
   cur.executemany("INSERT INTO lang VALUES(:name, :year)", data)

   # This is the qmark style used in a SELECT query:
   params = (1972,)
   cur.execute("SELECT * FROM lang WHERE first_appeared = ?", params)
   print(cur.fetchall())
   con.close()

Note:

  **PEP 249** numeric placeholders are *not* supported. If used, they
  will be interpreted as named placeholders.


How to adapt custom Python types to SQLite values
-------------------------------------------------

SQLite supports only a limited set of data types natively. To store
custom Python types in SQLite databases, *adapt* them to one of the
Python types SQLite natively understands.

There are two ways to adapt Python objects to SQLite types: letting
your object adapt itself, or using an *adapter callable*. The latter
will take precedence above the former. For a library that exports a
custom type, it may make sense to enable that type to adapt itself. As
an application developer, it may make more sense to take direct
control by registering custom adapter functions.


How to write adaptable objects
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Suppose we have a "Point" class that represents a pair of coordinates,
"x" and "y", in a Cartesian coordinate system. The coordinate pair
will be stored as a text string in the database, using a semicolon to
separate the coordinates. This can be implemented by adding a
"__conform__(self, protocol)" method which returns the adapted value.
The object passed to *protocol* will be of type "PrepareProtocol".

   class Point:
       def __init__(self, x, y):
           self.x, self.y = x, y

       def __conform__(self, protocol):
           if protocol is sqlite3.PrepareProtocol:
               return f"{self.x};{self.y}"

   con = sqlite3.connect(":memory:")
   cur = con.cursor()

   cur.execute("SELECT ?", (Point(4.0, -3.2),))
   print(cur.fetchone()[0])
   con.close()


How to register adapter callables
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

The other possibility is to create a function that converts the Python
object to an SQLite-compatible type. This function can then be
registered using "register_adapter()".

   class Point:
       def __init__(self, x, y):
           self.x, self.y = x, y

   def adapt_point(point):
       return f"{point.x};{point.y}"

   sqlite3.register_adapter(Point, adapt_point)

   con = sqlite3.connect(":memory:")
   cur = con.cursor()

   cur.execute("SELECT ?", (Point(1.0, 2.5),))
   print(cur.fetchone()[0])
   con.close()


How to convert SQLite values to custom Python types
---------------------------------------------------

Writing an adapter lets you convert *from* custom Python types *to*
SQLite values. To be able to convert *from* SQLite values *to* custom
Python types, we use *converters*.

Let's go back to the "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 "Point" object from it.

Note:

  Converter functions are **always** passed a "bytes" object, no
  matter the underlying SQLite data type.

   def convert_point(s):
       x, y = map(float, s.split(b";"))
       return Point(x, y)

We now need to tell "sqlite3" when it should convert a given SQLite
value. This is done when connecting to a database, using the
*detect_types* parameter of "connect()". There are three options:

* Implicit: set *detect_types* to "PARSE_DECLTYPES"

* Explicit: set *detect_types* to "PARSE_COLNAMES"

* Both: set *detect_types* to "sqlite3.PARSE_DECLTYPES |
  sqlite3.PARSE_COLNAMES". Column names take precedence over declared
  types.

The following example illustrates the implicit and explicit
approaches:

   class Point:
       def __init__(self, x, y):
           self.x, self.y = x, y

       def __repr__(self):
           return f"Point({self.x}, {self.y})"

   def adapt_point(point):
       return f"{point.x};{point.y}"

   def convert_point(s):
       x, y = list(map(float, s.split(b";")))
       return Point(x, y)

   # Register the adapter and converter
   sqlite3.register_adapter(Point, adapt_point)
   sqlite3.register_converter("point", convert_point)

   # 1) Parse using declared types
   p = Point(4.0, -3.2)
   con = sqlite3.connect(":memory:", detect_types=sqlite3.PARSE_DECLTYPES)
   cur = con.execute("CREATE TABLE test(p point)")

   cur.execute("INSERT INTO test(p) VALUES(?)", (p,))
   cur.execute("SELECT p FROM test")
   print("with declared types:", cur.fetchone()[0])
   cur.close()
   con.close()

   # 2) Parse using column names
   con = sqlite3.connect(":memory:", detect_types=sqlite3.PARSE_COLNAMES)
   cur = con.execute("CREATE TABLE test(p)")

   cur.execute("INSERT INTO test(p) VALUES(?)", (p,))
   cur.execute('SELECT p AS "p [point]" FROM test')
   print("with column names:", cur.fetchone()[0])
   cur.close()
   con.close()


Adapter and converter recipes
-----------------------------

This section shows recipes for common adapters and converters.

   import datetime
   import sqlite3

   def adapt_date_iso(val):
       """Adapt datetime.date to ISO 8601 date."""
       return val.isoformat()

   def adapt_datetime_iso(val):
       """Adapt datetime.datetime to timezone-naive ISO 8601 date."""
       return val.replace(tzinfo=None).isoformat()

   def adapt_datetime_epoch(val):
       """Adapt datetime.datetime to Unix timestamp."""
       return int(val.timestamp())

   sqlite3.register_adapter(datetime.date, adapt_date_iso)
   sqlite3.register_adapter(datetime.datetime, adapt_datetime_iso)
   sqlite3.register_adapter(datetime.datetime, adapt_datetime_epoch)

   def convert_date(val):
       """Convert ISO 8601 date to datetime.date object."""
       return datetime.date.fromisoformat(val.decode())

   def convert_datetime(val):
       """Convert ISO 8601 datetime to datetime.datetime object."""
       return datetime.datetime.fromisoformat(val.decode())

   def convert_timestamp(val):
       """Convert Unix epoch timestamp to datetime.datetime object."""
       return datetime.datetime.fromtimestamp(int(val))

   sqlite3.register_converter("date", convert_date)
   sqlite3.register_converter("datetime", convert_datetime)
   sqlite3.register_converter("timestamp", convert_timestamp)


How to use connection shortcut methods
--------------------------------------

Using the "execute()", "executemany()", and "executescript()" methods
of the "Connection" class, your code can be written more concisely
because you don't have to create the (often superfluous) "Cursor"
objects explicitly. Instead, the "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 "Connection" object.

   # Create and fill the table.
   con = sqlite3.connect(":memory:")
   con.execute("CREATE TABLE lang(name, first_appeared)")
   data = [
       ("C++", 1985),
       ("Objective-C", 1984),
   ]
   con.executemany("INSERT INTO lang(name, first_appeared) VALUES(?, ?)", data)

   # Print the table contents
   for row in con.execute("SELECT name, first_appeared FROM lang"):
       print(row)

   print("I just deleted", con.execute("DELETE FROM lang").rowcount, "rows")

   # close() is not a shortcut method and it's not called automatically;
   # the connection object should be closed manually
   con.close()


How to use the connection context manager
-----------------------------------------

A "Connection" object can be used as a context manager that
automatically commits or rolls back open transactions when leaving the
body of the context manager. If the body of the "with" statement
finishes without exceptions, the transaction is committed. If this
commit fails, or if the body of the "with" statement raises an
uncaught exception, the transaction is rolled back. If "autocommit" is
"False", a new transaction is implicitly opened after committing or
rolling back.

If there is no open transaction upon leaving the body of the "with"
statement, or if "autocommit" is "True", the context manager does
nothing.

Note:

  The context manager neither implicitly opens a new transaction nor
  closes the connection. If you need a closing context manager,
  consider using "contextlib.closing()".

   con = sqlite3.connect(":memory:")
   con.execute("CREATE TABLE lang(id INTEGER PRIMARY KEY, name VARCHAR UNIQUE)")

   # Successful, con.commit() is called automatically afterwards
   with con:
       con.execute("INSERT INTO lang(name) VALUES(?)", ("Python",))

   # con.rollback() is called after the with block finishes with an exception,
   # the exception is still raised and must be caught
   try:
       with con:
           con.execute("INSERT INTO lang(name) VALUES(?)", ("Python",))
   except sqlite3.IntegrityError:
       print("couldn't add Python twice")

   # Connection object used as context manager only commits or rollbacks transactions,
   # so the connection object should be closed manually
   con.close()


How to work with SQLite URIs
----------------------------

Some useful URI tricks include:

* Open a database in read-only mode:

   >>> con = sqlite3.connect("file:tutorial.db?mode=ro", uri=True)
   >>> con.execute("CREATE TABLE readonly(data)")
   Traceback (most recent call last):
   OperationalError: attempt to write a readonly database
   >>> con.close()

* Do not implicitly create a new database file if it does not already
  exist; will raise "OperationalError" if unable to create a new file:

   >>> con = sqlite3.connect("file:nosuchdb.db?mode=rw", uri=True)
   Traceback (most recent call last):
   OperationalError: unable to open database file

* Create a shared named in-memory database:

   db = "file:mem1?mode=memory&cache=shared"
   con1 = sqlite3.connect(db, uri=True)
   con2 = sqlite3.connect(db, uri=True)
   with con1:
       con1.execute("CREATE TABLE shared(data)")
       con1.execute("INSERT INTO shared VALUES(28)")
   res = con2.execute("SELECT data FROM shared")
   assert res.fetchone() == (28,)

   con1.close()
   con2.close()

More information about this feature, including a list of parameters,
can be found in the SQLite URI documentation.


How to create and use row factories
-----------------------------------

By default, "sqlite3" represents each row as a "tuple". If a "tuple"
does not suit your needs, you can use the "sqlite3.Row" class or a
custom "row_factory".

While "row_factory" exists as an attribute both on the "Cursor" and
the "Connection", it is recommended to set "Connection.row_factory",
so all cursors created from the connection will use the same row
factory.

"Row" provides indexed and case-insensitive named access to columns,
with minimal memory overhead and performance impact over a "tuple". To
use "Row" as a row factory, assign it to the "row_factory" attribute:

   >>> con = sqlite3.connect(":memory:")
   >>> con.row_factory = sqlite3.Row

Queries now return "Row" objects:

   >>> res = con.execute("SELECT 'Earth' AS name, 6378 AS radius")
   >>> row = res.fetchone()
   >>> row.keys()
   ['name', 'radius']
   >>> row[0]         # Access by index.
   'Earth'
   >>> row["name"]    # Access by name.
   'Earth'
   >>> row["RADIUS"]  # Column names are case-insensitive.
   6378
   >>> con.close()

Note:

  The "FROM" clause can be omitted in the "SELECT" statement, as in
  the above example. In such cases, SQLite returns a single row with
  columns defined by expressions, e.g. literals, with the given
  aliases "expr AS alias".

You can create a custom "row_factory" that returns each row as a
"dict", with column names mapped to values:

   def dict_factory(cursor, row):
       fields = [column[0] for column in cursor.description]
       return {key: value for key, value in zip(fields, row)}

Using it, queries now return a "dict" instead of a "tuple":

   >>> con = sqlite3.connect(":memory:")
   >>> con.row_factory = dict_factory
   >>> for row in con.execute("SELECT 1 AS a, 2 AS b"):
   ...     print(row)
   {'a': 1, 'b': 2}
   >>> con.close()

The following row factory returns a *named tuple*:

   from collections import namedtuple

   def namedtuple_factory(cursor, row):
       fields = [column[0] for column in cursor.description]
       cls = namedtuple("Row", fields)
       return cls._make(row)

"namedtuple_factory()" can be used as follows:

   >>> con = sqlite3.connect(":memory:")
   >>> con.row_factory = namedtuple_factory
   >>> cur = con.execute("SELECT 1 AS a, 2 AS b")
   >>> row = cur.fetchone()
   >>> row
   Row(a=1, b=2)
   >>> row[0]  # Indexed access.
   1
   >>> row.b   # Attribute access.
   2
   >>> con.close()

With some adjustments, the above recipe can be adapted to use a
"dataclass", or any other custom class, instead of a "namedtuple".


How to handle non-UTF-8 text encodings
--------------------------------------

By default, "sqlite3" uses "str" to adapt SQLite values with the
"TEXT" data type. This works well for UTF-8 encoded text, but it might
fail for other encodings and invalid UTF-8. You can use a custom
"text_factory" to handle such cases.

Because of SQLite's flexible typing, it is not uncommon to encounter
table columns with the "TEXT" data type containing non-UTF-8
encodings, or even arbitrary data. To demonstrate, let's assume we
have a database with ISO-8859-2 (Latin-2) encoded text, for example a
table of Czech-English dictionary entries. Assuming we now have a
"Connection" instance "con" connected to this database, we can decode
the Latin-2 encoded text using this "text_factory":

   con.text_factory = lambda data: str(data, encoding="latin2")

For invalid UTF-8 or arbitrary data in stored in "TEXT" table columns,
you can use the following technique, borrowed from the Guide Unicode:

   con.text_factory = lambda data: str(data, errors="surrogateescape")

Note:

  The "sqlite3" module API does not support strings containing
  surrogates.

Voir aussi: Guide Unicode


Explanation
===========


Transaction control
-------------------

"sqlite3" offers multiple methods of controlling whether, when and how
database transactions are opened and closed. Transaction control via
the autocommit attribute is recommended, while Transaction control via
the isolation_level attribute retains the pre-Python 3.12 behaviour.


Transaction control via the "autocommit" attribute
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

The recommended way of controlling transaction behaviour is through
the "Connection.autocommit" attribute, which should preferably be set
using the *autocommit* parameter of "connect()".

It is suggested to set *autocommit* to "False", which implies **PEP
249**-compliant transaction control. This means:

* "sqlite3" ensures that a transaction is always open, so "connect()",
  "Connection.commit()", and "Connection.rollback()" will implicitly
  open a new transaction (immediately after closing the pending one,
  for the latter two). "sqlite3" uses "BEGIN DEFERRED" statements when
  opening transactions.

* Transactions should be committed explicitly using "commit()".

* Transactions should be rolled back explicitly using "rollback()".

* An implicit rollback is performed if the database is "close()"-ed
  with pending changes.

Set *autocommit* to "True" to enable SQLite's autocommit mode. In this
mode, "Connection.commit()" and "Connection.rollback()" have no
effect. Note that SQLite's autocommit mode is distinct from the **PEP
249**-compliant "Connection.autocommit" attribute; use
"Connection.in_transaction" to query the low-level SQLite autocommit
mode.

Set *autocommit* to "LEGACY_TRANSACTION_CONTROL" to leave transaction
control behaviour to the "Connection.isolation_level" attribute. See
Transaction control via the isolation_level attribute for more
information.


Transaction control via the "isolation_level" attribute
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Note:

  The recommended way of controlling transactions is via the
  "autocommit" attribute. See Transaction control via the autocommit
  attribute.

If "Connection.autocommit" is set to "LEGACY_TRANSACTION_CONTROL" (the
default), transaction behaviour is controlled using the
"Connection.isolation_level" attribute. Otherwise, "isolation_level"
has no effect.

If the connection attribute "isolation_level" is not "None", new
transactions are implicitly opened before "execute()" and
"executemany()" executes "INSERT", "UPDATE", "DELETE", or "REPLACE"
statements; for other statements, no implicit transaction handling is
performed. Use the "commit()" and "rollback()" methods to respectively
commit and roll back pending transactions. You can choose the
underlying SQLite transaction behaviour — that is, whether and what
type of "BEGIN" statements "sqlite3" implicitly executes – via the
"isolation_level" attribute.

If "isolation_level" is set to "None", no transactions are implicitly
opened at all. This leaves the underlying SQLite library in autocommit
mode, but also allows the user to perform their own transaction
handling using explicit SQL statements. The underlying SQLite library
autocommit mode can be queried using the "in_transaction" attribute.

The "executescript()" method implicitly commits any pending
transaction before execution of the given SQL script, regardless of
the value of "isolation_level".

Modifié dans la version 3.6: "sqlite3" used to implicitly commit an
open transaction before DDL statements.  This is no longer the case.

Modifié dans la version 3.12: The recommended way of controlling
transactions is now via the "autocommit" attribute.
