Class ARRAY

lib/sqlalchemy/dialects/postgresql/array.py:238–486

PostgreSQL ARRAY type. The :class:`_postgresql.ARRAY` type is constructed in the same way as the core :class:`_types.ARRAY` type; a member type is required, and a number of dimensions is recommended if the type is to be used for more than one dimension:: from sqlalchemy.dia

class ARRAY(sqltypes.ARRAY[_T]):
    """PostgreSQL ARRAY type.

    The :class:`_postgresql.ARRAY` type is constructed in the same way
    as the core :class:`_types.ARRAY` type; a member type is required, and a
    number of dimensions is recommended if the type is to be used for more
    than one dimension::

        from sqlalchemy.dialects import postgresql

        mytable = Table(
            "mytable",
            metadata,
            Column("data", postgresql.ARRAY(Integer, dimensions=2)),
        )

    The :class:`_postgresql.ARRAY` type provides all operations defined on the
    core :class:`_types.ARRAY` type, including support for "dimensions",
    indexed access, and simple matching such as
    :meth:`.types.ARRAY.Comparator.any` and
    :meth:`.types.ARRAY.Comparator.all`.  :class:`_postgresql.ARRAY`
    class also
    provides PostgreSQL-specific methods for containment operations, including
    :meth:`.postgresql.ARRAY.Comparator.contains`
    :meth:`.postgresql.ARRAY.Comparator.contained_by`, and
    :meth:`.postgresql.ARRAY.Comparator.overlap`, e.g.::

        mytable.c.data.contains([1, 2])

    Indexed access is one-based by default, to match that of PostgreSQL;
    for zero-based indexed access, set
    :paramref:`_postgresql.ARRAY.zero_indexes`.

    Additionally, the :class:`_postgresql.ARRAY`
    type does not work directly in
    conjunction with the :class:`.ENUM` type.  For a workaround, see the
    special type at :ref:`postgresql_array_of_enum`.

    .. container:: topic

        **Detecting Changes in ARRAY columns when using the ORM**

        The :class:`_postgresql.ARRAY` type, when used with the SQLAlchemy ORM,
        does not detect in-place mutations to the array. In order to detect
        these, the :mod:`sqlalchemy.ext.mutable` extension must be used, using
        the :class:`.MutableList` class::

            from sqlalchemy.dialects.postgresql import ARRAY
            from sqlalchemy.ext.mutable import MutableList


            class SomeOrmClass(Base):
                # ...

                data = Column(MutableList.as_mutable(ARRAY(Integer)))

        This extension will allow "in-place" changes such to the array
        such as ``.append()`` to produce events which will be detected by the