Class CreateView

lib/sqlalchemy/sql/ddl.py:758–895

Represent a CREATE VIEW statement. This creates a new view based on a particular SELECT statement. The schema of the view is based on the columns of the SELECT statement, and the data present in the view is derived from the rows represented by the SELECT. A non-materialized view wi

class CreateView(DialectKWArgs, _TableViaSelect):
    """Represent a CREATE VIEW statement.

    This creates a new view based on a particular SELECT statement. The schema
    of the view is based on the columns of the SELECT statement, and the data
    present in the view is derived from the rows represented by the
    SELECT.  A non-materialized view will evaluate the SELECT statement
    dynamically as it is queried, whereas a materialized view represents a
    snapshot of the SELECT statement at a particular point in time and
    typically needs to be refreshed manually using database-specific commands.

    The example below illustrates basic use of :class:`.CreateView`; given a
    :class:`.Select` and optional :class:`.MetaData`, the
    :class:`.CreateView` may be invoked directly via
    :meth:`.Connection.execute` or indirectly via :meth:`.MetaData.create_all`;
    the :attr:`.CreateView.table` attribute provides a :class:`.Table`
    object with which to generate new queries::


        from sqlalchemy import select
        from sqlalchemy.sql.ddl import CreateView

        # instantiate CreateView given a select() and optional MetaData
        create_view = CreateView(
            select(users.c.id, users.c.name).where(users.c.status == "active"),
            "active_users_view",
            metadata=some_metadata,
        )

        # a Table object is available immediately via the .table attribute
        new_statement = select(create_view.table)

        # to emit CREATE VIEW, either invoke CreateView directly...
        with engine.begin() as conn:
            conn.execute(create_view)

        # or alternatively, invoke metadata.create_all()
        some_metdata.create_all(engine)

        # drop is performed in the usual way, via drop_all
        # or table.drop() (will emit DROP VIEW)
        some_metdata.drop_all(engine)

    For detailed background on :class:`.CreateView` see
    :ref:`metadata_create_view`.

    .. versionadded:: 2.1

    :param selectable: :class:`_sql.Select`
        The SELECT statement defining the view.

    :param view_name: table name as a string. Combine with the optional
        :paramref:`.CreateView.schema` parameter to indicate a
        schema-qualified table name.

    :param metadata: :class:`_schema.MetaData`, optional
        If provided, the :class:`_schema.Table` object available via the
        :attr:`.table` attribute will be associated with this