sqlalchemy.dialects.postgresql.ExcludeConstraint

Create an :class:`.ExcludeConstraint` object. E.g.:: const = ExcludeConstraint( (Column('period'), '&&'), (Column('group'), '='), where=(Column('group') != 'some group'), ops={'group': 'my_operator_class'} ) The constraint is normally embedded into the :class:`_schema.Table` construct directly, or added later using :meth:`.append_constraint`:: some_table = Table( 'some_table', metadata, Column('id', Integer, primary_key=True), Column('period', TSRANGE()), Column('group', String) ) some_table.append_constraint( ExcludeConstraint( (some_table.c.period, '&&'), (some_table.c.group, '='), where=some_table.c.group != 'some group', name='some_table_excl_const', ops={'group': 'my_operator_class'} ) ) :param \*elements: A sequence of two tuples of the form ``(column, operator)`` where "column" is either a :class:`_schema.Column` object, or a SQL expression element (e.g. ``func.int8range(table.from, table.to)``) or the name of a column as string, and "operator" is a string containing the operator to use (e.g. `"&&"` or `"="`). In order to specify a column name when a :class:`_schema.Column` object is not available, while ensuring that any necessary quoting rules take effect, an ad-hoc :class:`_schema.Column` or :func:`_expression.column` object should be used. The ``column`` may also be a string SQL expression when passed as :func:`_expression.literal_column` or :func:`_expression.text` :param name: Optional, the in-database name of this constraint. :param deferrable: Optional bool. If set, emit DEFERRABLE or NOT DEFERRABLE when issuing DDL for this constraint. :param initially: Optional string. If set, emit INITIALLY <value> when issuing DDL for this constraint. :param using: Optional string. If set, emit USING <index_method> when issuing DDL for this constraint. Defaults to 'gist'. :param where: Optional SQL expression construct or literal SQL string. If set, emit WHERE <predicate> when issuing DDL for this constraint. :param ops: Optional dictionary. Used to define operator classes for the elements; works the same way as that of the :ref:`postgresql_ops <postgresql_operator_classes>` parameter specified to the :class:`_schema.Index` construct. .. versionadded:: 1.3.21 .. seealso:: :ref:`postgresql_operator_classes` - general description of how PostgreSQL operator classes are specified.