Classe « Sequence »

Informations générales

Héritage

    builtins.object
        Visitable
builtins.object
    EventTarget
        SchemaEventTarget
            SchemaItem
builtins.object
    SQLRole
        StatementRole
            Executable
                DefaultGenerator
            builtins.object
                IdentityOptions
    builtins.object
        Visitable
builtins.object
    EventTarget
        SchemaEventTarget
            SchemaItem
                HasSchemaAttr
                    Sequence

Définition

class Sequence(HasSchemaAttr, IdentityOptions, DefaultGenerator):

help(Sequence)

Represents a named database sequence.

The :class:`.Sequence` object represents the name and configurational
parameters of a database sequence.   It also represents
a construct that can be "executed" by a SQLAlchemy :class:`_engine.Engine`
or :class:`_engine.Connection`,
rendering the appropriate "next value" function
for the target database and returning a result.

The :class:`.Sequence` is typically associated with a primary key column::

    some_table = Table(
        "some_table",
        metadata,
        Column(
            "id",
            Integer,
            Sequence("some_table_seq", start=1),
            primary_key=True,
        ),
    )

When CREATE TABLE is emitted for the above :class:`_schema.Table`, if the
target platform supports sequences, a CREATE SEQUENCE statement will
be emitted as well.   For platforms that don't support sequences,
the :class:`.Sequence` construct is ignored.

.. seealso::

    :ref:`defaults_sequences`

    :class:`.CreateSequence`

    :class:`.DropSequence`

Constructeur(s)

Signature du constructeur	Description
__init__(self, name: 'str', start: 'Optional[int]' = None, increment: 'Optional[int]' = None, minvalue: 'Optional[int]' = None, maxvalue: 'Optional[int]' = None, nominvalue: 'Optional[bool]' = None, nomaxvalue: 'Optional[bool]' = None, cycle: 'Optional[bool]' = None, schema: 'Optional[Union[str, Literal[SchemaConst.BLANK_SCHEMA]]]' = None, cache: 'Optional[int]' = None, order: 'Optional[bool]' = None, data_type: 'Optional[_TypeEngineArgument[int]]' = None, optional: 'bool' = False, quote: 'Optional[bool]' = None, metadata: 'Optional[MetaData]' = None, quote_schema: 'Optional[bool]' = None, for_update: 'bool' = False) -> 'None'	Construct a :class:`.Sequence` object. _{[extrait de __init__.__doc__]}

__init__(self, name: 'str', start: 'Optional[int]' = None, increment: 'Optional[int]' = None, minvalue: 'Optional[int]' = None, maxvalue: 'Optional[int]' = None, nominvalue: 'Optional[bool]' = None, nomaxvalue: 'Optional[bool]' = None, cycle: 'Optional[bool]' = None, schema: 'Optional[Union[str, Literal[SchemaConst.BLANK_SCHEMA]]]' = None, cache: 'Optional[int]' = None, order: 'Optional[bool]' = None, data_type: 'Optional[_TypeEngineArgument[int]]' = None, optional: 'bool' = False, quote: 'Optional[bool]' = None, metadata: 'Optional[MetaData]' = None, quote_schema: 'Optional[bool]' = None, for_update: 'bool' = False) -> 'None'

Construct a :class:`.Sequence` object. _{[extrait de __init__.__doc__]}

Liste des attributs statiques

Nom de l'attribut	Valeur
allows_lambda	False
create_drop_stringify_dialect	default
dispatch	<sqlalchemy.event.base.DDLEventsDispatch object at 0x0000020D9F843260>
has_arg	False
info	<sqlalchemy.util.langhelpers._memoized_property object at 0x0000020D9F80A270>
is_callable	False
is_clause_element	False
is_delete	False
is_dml	False
is_from_statement	False
is_identity	False
is_insert	False
is_scalar	False
is_select	False
is_sentinel	False
is_sequence	True
is_server_default	False
is_text	False
is_update	False
supports_execution	True
uses_inspection	False

Liste des opérateurs

Opérateurs hérités de la classe object

__eq__, __ge__, __gt__, __le__, __lt__, __ne__

Liste des méthodes

Toutes les méthodes Méthodes d'instance Méthodes statiques

Signature de la méthode	Description
create(self, bind: '_CreateDropBind', checkfirst: 'bool' = True) -> 'None'	Creates this sequence in the database. _{[extrait de create.__doc__]}
drop(self, bind: '_CreateDropBind', checkfirst: 'bool' = True) -> 'None'	Drops this sequence from the database. _{[extrait de drop.__doc__]}
next_value(self) -> 'Function[int]'	Return a :class:`.next_value` function element _{[extrait de next_value.__doc__]}