Class Sequence

lib/sqlalchemy/sql/schema.py:4052–4350

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`, renderin

class Sequence(HasSchemaAttr, IdentityOptions, DefaultGenerator):
    """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`

    """

    __visit_name__ = "sequence"

    is_sequence = True

    column: Optional[Column[Any]]
    data_type: Optional[TypeEngine[int]]

    metadata: Optional[MetaData]

    @util.deprecated_params(
        order=(
            "2.1",
            "This parameter is supported only by Oracle Database, "
            "use ``oracle_order`` instead.",
        )
    )
    def __init__(
        self,
        name: str,
        start: Optional[int] = None,