Viewing file:  ranges.py (4.64 KB) -rw-r--r--
Select action/file-type:
 (+) |  (+) |  (+) | Code (+) | Session (+) |  (+) | SDB (+) |  (+) |  (+) |  (+) |  (+) |  (+) |
# Copyright (C) 2013-2019 the SQLAlchemy authors and contributors
# <see AUTHORS file>
#
# This module is part of SQLAlchemy and is released under
# the MIT License: http://www.opensource.org/licenses/mit-license.php
from .base import ischema_names
from ... import types as sqltypes
__all__ = ("INT4RANGE", "INT8RANGE", "NUMRANGE")
class RangeOperators(object):
"""
This mixin provides functionality for the Range Operators
listed in Table 9-44 of the `postgres documentation`__ for Range
Functions and Operators. It is used by all the range types
provided in the ``postgres`` dialect and can likely be used for
any range types you create yourself.
__ http://www.postgresql.org/docs/devel/static/functions-range.html
No extra support is provided for the Range Functions listed in
Table 9-45 of the postgres documentation. For these, the normal
:func:`~sqlalchemy.sql.expression.func` object should be used.
"""
class comparator_factory(sqltypes.Concatenable.Comparator):
"""Define comparison operations for range types."""
def __ne__(self, other):
"Boolean expression. Returns true if two ranges are not equal"
if other is None:
return super(RangeOperators.comparator_factory, self).__ne__(
other
)
else:
return self.expr.op("<>")(other)
def contains(self, other, **kw):
"""Boolean expression. Returns true if the right hand operand,
which can be an element or a range, is contained within the
column.
"""
return self.expr.op("@>")(other)
def contained_by(self, other):
"""Boolean expression. Returns true if the column is contained
within the right hand operand.
"""
return self.expr.op("<@")(other)
def overlaps(self, other):
"""Boolean expression. Returns true if the column overlaps
(has points in common with) the right hand operand.
"""
return self.expr.op("&&")(other)
def strictly_left_of(self, other):
"""Boolean expression. Returns true if the column is strictly
left of the right hand operand.
"""
return self.expr.op("<<")(other)
__lshift__ = strictly_left_of
def strictly_right_of(self, other):
"""Boolean expression. Returns true if the column is strictly
right of the right hand operand.
"""
return self.expr.op(">>")(other)
__rshift__ = strictly_right_of
def not_extend_right_of(self, other):
"""Boolean expression. Returns true if the range in the column
does not extend right of the range in the operand.
"""
return self.expr.op("&<")(other)
def not_extend_left_of(self, other):
"""Boolean expression. Returns true if the range in the column
does not extend left of the range in the operand.
"""
return self.expr.op("&>")(other)
def adjacent_to(self, other):
"""Boolean expression. Returns true if the range in the column
is adjacent to the range in the operand.
"""
return self.expr.op("-|-")(other)
def __add__(self, other):
"""Range expression. Returns the union of the two ranges.
Will raise an exception if the resulting range is not
contigous.
"""
return self.expr.op("+")(other)
class INT4RANGE(RangeOperators, sqltypes.TypeEngine):
"""Represent the PostgreSQL INT4RANGE type.
"""
__visit_name__ = "INT4RANGE"
ischema_names["int4range"] = INT4RANGE
class INT8RANGE(RangeOperators, sqltypes.TypeEngine):
"""Represent the PostgreSQL INT8RANGE type.
"""
__visit_name__ = "INT8RANGE"
ischema_names["int8range"] = INT8RANGE
class NUMRANGE(RangeOperators, sqltypes.TypeEngine):
"""Represent the PostgreSQL NUMRANGE type.
"""
__visit_name__ = "NUMRANGE"
ischema_names["numrange"] = NUMRANGE
class DATERANGE(RangeOperators, sqltypes.TypeEngine):
"""Represent the PostgreSQL DATERANGE type.
"""
__visit_name__ = "DATERANGE"
ischema_names["daterange"] = DATERANGE
class TSRANGE(RangeOperators, sqltypes.TypeEngine):
"""Represent the PostgreSQL TSRANGE type.
"""
__visit_name__ = "TSRANGE"
ischema_names["tsrange"] = TSRANGE
class TSTZRANGE(RangeOperators, sqltypes.TypeEngine):
"""Represent the PostgreSQL TSTZRANGE type.
"""
__visit_name__ = "TSTZRANGE"
ischema_names["tstzrange"] = TSTZRANGE
|