1503 lines
42 KiB
Python
1503 lines
42 KiB
Python
# sql/operators.py
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# Copyright (C) 2005-2019 the SQLAlchemy authors and contributors
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# <see AUTHORS file>
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#
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# This module is part of SQLAlchemy and is released under
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# the MIT License: http://www.opensource.org/licenses/mit-license.php
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# This module is part of SQLAlchemy and is released under
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# the MIT License: http://www.opensource.org/licenses/mit-license.php
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"""Defines operators used in SQL expressions."""
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from operator import add
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from operator import and_
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from operator import contains
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from operator import eq
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from operator import ge
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from operator import getitem
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from operator import gt
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from operator import inv
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from operator import le
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from operator import lshift
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from operator import lt
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from operator import mod
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from operator import mul
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from operator import ne
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from operator import neg
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from operator import or_
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from operator import rshift
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from operator import sub
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from operator import truediv
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from .. import util
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if util.py2k:
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from operator import div
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else:
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div = truediv
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class Operators(object):
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"""Base of comparison and logical operators.
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Implements base methods
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:meth:`~sqlalchemy.sql.operators.Operators.operate` and
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:meth:`~sqlalchemy.sql.operators.Operators.reverse_operate`, as well as
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:meth:`~sqlalchemy.sql.operators.Operators.__and__`,
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:meth:`~sqlalchemy.sql.operators.Operators.__or__`,
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:meth:`~sqlalchemy.sql.operators.Operators.__invert__`.
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Usually is used via its most common subclass
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:class:`.ColumnOperators`.
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"""
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__slots__ = ()
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def __and__(self, other):
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"""Implement the ``&`` operator.
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When used with SQL expressions, results in an
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AND operation, equivalent to
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:func:`~.expression.and_`, that is::
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a & b
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is equivalent to::
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from sqlalchemy import and_
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and_(a, b)
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Care should be taken when using ``&`` regarding
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operator precedence; the ``&`` operator has the highest precedence.
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The operands should be enclosed in parenthesis if they contain
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further sub expressions::
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(a == 2) & (b == 4)
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"""
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return self.operate(and_, other)
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def __or__(self, other):
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"""Implement the ``|`` operator.
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When used with SQL expressions, results in an
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OR operation, equivalent to
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:func:`~.expression.or_`, that is::
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a | b
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is equivalent to::
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from sqlalchemy import or_
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or_(a, b)
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Care should be taken when using ``|`` regarding
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operator precedence; the ``|`` operator has the highest precedence.
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The operands should be enclosed in parenthesis if they contain
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further sub expressions::
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(a == 2) | (b == 4)
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"""
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return self.operate(or_, other)
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def __invert__(self):
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"""Implement the ``~`` operator.
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When used with SQL expressions, results in a
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NOT operation, equivalent to
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:func:`~.expression.not_`, that is::
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~a
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is equivalent to::
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from sqlalchemy import not_
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not_(a)
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"""
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return self.operate(inv)
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def op(
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self, opstring, precedence=0, is_comparison=False, return_type=None
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):
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"""produce a generic operator function.
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e.g.::
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somecolumn.op("*")(5)
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produces::
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somecolumn * 5
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This function can also be used to make bitwise operators explicit. For
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example::
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somecolumn.op('&')(0xff)
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is a bitwise AND of the value in ``somecolumn``.
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:param operator: a string which will be output as the infix operator
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between this element and the expression passed to the
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generated function.
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:param precedence: precedence to apply to the operator, when
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parenthesizing expressions. A lower number will cause the expression
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to be parenthesized when applied against another operator with
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higher precedence. The default value of ``0`` is lower than all
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operators except for the comma (``,``) and ``AS`` operators.
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A value of 100 will be higher or equal to all operators, and -100
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will be lower than or equal to all operators.
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:param is_comparison: if True, the operator will be considered as a
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"comparison" operator, that is which evaluates to a boolean
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true/false value, like ``==``, ``>``, etc. This flag should be set
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so that ORM relationships can establish that the operator is a
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comparison operator when used in a custom join condition.
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.. versionadded:: 0.9.2 - added the
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:paramref:`.Operators.op.is_comparison` flag.
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:param return_type: a :class:`.TypeEngine` class or object that will
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force the return type of an expression produced by this operator
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to be of that type. By default, operators that specify
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:paramref:`.Operators.op.is_comparison` will resolve to
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:class:`.Boolean`, and those that do not will be of the same
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type as the left-hand operand.
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.. versionadded:: 1.2.0b3 - added the
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:paramref:`.Operators.op.return_type` argument.
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.. seealso::
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:ref:`types_operators`
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:ref:`relationship_custom_operator`
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"""
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operator = custom_op(opstring, precedence, is_comparison, return_type)
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def against(other):
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return operator(self, other)
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return against
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def bool_op(self, opstring, precedence=0):
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"""Return a custom boolean operator.
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This method is shorthand for calling
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:meth:`.Operators.op` and passing the
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:paramref:`.Operators.op.is_comparison`
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flag with True.
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.. versionadded:: 1.2.0b3
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.. seealso::
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:meth:`.Operators.op`
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"""
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return self.op(opstring, precedence=precedence, is_comparison=True)
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def operate(self, op, *other, **kwargs):
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r"""Operate on an argument.
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This is the lowest level of operation, raises
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:class:`NotImplementedError` by default.
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Overriding this on a subclass can allow common
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behavior to be applied to all operations.
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For example, overriding :class:`.ColumnOperators`
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to apply ``func.lower()`` to the left and right
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side::
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class MyComparator(ColumnOperators):
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def operate(self, op, other):
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return op(func.lower(self), func.lower(other))
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:param op: Operator callable.
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:param \*other: the 'other' side of the operation. Will
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be a single scalar for most operations.
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:param \**kwargs: modifiers. These may be passed by special
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operators such as :meth:`ColumnOperators.contains`.
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"""
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raise NotImplementedError(str(op))
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def reverse_operate(self, op, other, **kwargs):
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"""Reverse operate on an argument.
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Usage is the same as :meth:`operate`.
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"""
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raise NotImplementedError(str(op))
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class custom_op(object):
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"""Represent a 'custom' operator.
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:class:`.custom_op` is normally instantiated when the
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:meth:`.Operators.op` or :meth:`.Operators.bool_op` methods
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are used to create a custom operator callable. The class can also be
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used directly when programmatically constructing expressions. E.g.
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to represent the "factorial" operation::
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from sqlalchemy.sql import UnaryExpression
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from sqlalchemy.sql import operators
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from sqlalchemy import Numeric
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unary = UnaryExpression(table.c.somecolumn,
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modifier=operators.custom_op("!"),
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type_=Numeric)
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.. seealso::
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:meth:`.Operators.op`
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:meth:`.Operators.bool_op`
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"""
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__name__ = "custom_op"
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def __init__(
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self,
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opstring,
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precedence=0,
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is_comparison=False,
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return_type=None,
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natural_self_precedent=False,
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eager_grouping=False,
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):
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self.opstring = opstring
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self.precedence = precedence
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self.is_comparison = is_comparison
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self.natural_self_precedent = natural_self_precedent
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self.eager_grouping = eager_grouping
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self.return_type = (
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return_type._to_instance(return_type) if return_type else None
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)
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def __eq__(self, other):
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return isinstance(other, custom_op) and other.opstring == self.opstring
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def __hash__(self):
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return id(self)
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def __call__(self, left, right, **kw):
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return left.operate(self, right, **kw)
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class ColumnOperators(Operators):
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"""Defines boolean, comparison, and other operators for
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:class:`.ColumnElement` expressions.
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By default, all methods call down to
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:meth:`.operate` or :meth:`.reverse_operate`,
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passing in the appropriate operator function from the
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Python builtin ``operator`` module or
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a SQLAlchemy-specific operator function from
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:mod:`sqlalchemy.expression.operators`. For example
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the ``__eq__`` function::
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def __eq__(self, other):
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return self.operate(operators.eq, other)
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Where ``operators.eq`` is essentially::
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def eq(a, b):
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return a == b
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The core column expression unit :class:`.ColumnElement`
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overrides :meth:`.Operators.operate` and others
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to return further :class:`.ColumnElement` constructs,
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so that the ``==`` operation above is replaced by a clause
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construct.
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.. seealso::
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:ref:`types_operators`
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:attr:`.TypeEngine.comparator_factory`
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:class:`.ColumnOperators`
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:class:`.PropComparator`
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"""
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__slots__ = ()
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timetuple = None
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"""Hack, allows datetime objects to be compared on the LHS."""
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def __lt__(self, other):
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"""Implement the ``<`` operator.
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In a column context, produces the clause ``a < b``.
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"""
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return self.operate(lt, other)
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def __le__(self, other):
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"""Implement the ``<=`` operator.
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In a column context, produces the clause ``a <= b``.
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"""
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return self.operate(le, other)
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__hash__ = Operators.__hash__
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def __eq__(self, other):
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"""Implement the ``==`` operator.
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In a column context, produces the clause ``a = b``.
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If the target is ``None``, produces ``a IS NULL``.
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"""
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return self.operate(eq, other)
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def __ne__(self, other):
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"""Implement the ``!=`` operator.
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In a column context, produces the clause ``a != b``.
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If the target is ``None``, produces ``a IS NOT NULL``.
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"""
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return self.operate(ne, other)
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def is_distinct_from(self, other):
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"""Implement the ``IS DISTINCT FROM`` operator.
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Renders "a IS DISTINCT FROM b" on most platforms;
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on some such as SQLite may render "a IS NOT b".
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.. versionadded:: 1.1
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"""
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return self.operate(is_distinct_from, other)
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def isnot_distinct_from(self, other):
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"""Implement the ``IS NOT DISTINCT FROM`` operator.
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Renders "a IS NOT DISTINCT FROM b" on most platforms;
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on some such as SQLite may render "a IS b".
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.. versionadded:: 1.1
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"""
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return self.operate(isnot_distinct_from, other)
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def __gt__(self, other):
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"""Implement the ``>`` operator.
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In a column context, produces the clause ``a > b``.
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"""
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return self.operate(gt, other)
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def __ge__(self, other):
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"""Implement the ``>=`` operator.
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In a column context, produces the clause ``a >= b``.
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"""
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return self.operate(ge, other)
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def __neg__(self):
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"""Implement the ``-`` operator.
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In a column context, produces the clause ``-a``.
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"""
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return self.operate(neg)
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def __contains__(self, other):
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return self.operate(contains, other)
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def __getitem__(self, index):
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"""Implement the [] operator.
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This can be used by some database-specific types
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such as PostgreSQL ARRAY and HSTORE.
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"""
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return self.operate(getitem, index)
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def __lshift__(self, other):
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"""implement the << operator.
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Not used by SQLAlchemy core, this is provided
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for custom operator systems which want to use
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<< as an extension point.
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"""
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return self.operate(lshift, other)
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def __rshift__(self, other):
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"""implement the >> operator.
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Not used by SQLAlchemy core, this is provided
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for custom operator systems which want to use
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>> as an extension point.
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"""
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return self.operate(rshift, other)
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def concat(self, other):
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"""Implement the 'concat' operator.
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In a column context, produces the clause ``a || b``,
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or uses the ``concat()`` operator on MySQL.
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"""
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return self.operate(concat_op, other)
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def like(self, other, escape=None):
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r"""Implement the ``like`` operator.
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In a column context, produces the expression::
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a LIKE other
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E.g.::
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stmt = select([sometable]).\
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where(sometable.c.column.like("%foobar%"))
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:param other: expression to be compared
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:param escape: optional escape character, renders the ``ESCAPE``
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keyword, e.g.::
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somecolumn.like("foo/%bar", escape="/")
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.. seealso::
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:meth:`.ColumnOperators.ilike`
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"""
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return self.operate(like_op, other, escape=escape)
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def ilike(self, other, escape=None):
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r"""Implement the ``ilike`` operator, e.g. case insensitive LIKE.
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In a column context, produces an expression either of the form::
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lower(a) LIKE lower(other)
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Or on backends that support the ILIKE operator::
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a ILIKE other
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E.g.::
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stmt = select([sometable]).\
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where(sometable.c.column.ilike("%foobar%"))
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:param other: expression to be compared
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:param escape: optional escape character, renders the ``ESCAPE``
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keyword, e.g.::
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somecolumn.ilike("foo/%bar", escape="/")
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.. seealso::
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:meth:`.ColumnOperators.like`
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"""
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return self.operate(ilike_op, other, escape=escape)
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def in_(self, other):
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"""Implement the ``in`` operator.
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In a column context, produces the clause ``column IN <other>``.
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The given parameter ``other`` may be:
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* A list of literal values, e.g.::
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stmt.where(column.in_([1, 2, 3]))
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In this calling form, the list of items is converted to a set of
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bound parameters the same length as the list given::
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WHERE COL IN (?, ?, ?)
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* A list of tuples may be provided if the comparison is against a
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:func:`.tuple_` containing multiple expressions::
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from sqlalchemy import tuple_
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stmt.where(tuple_(col1, col2).in_([(1, 10), (2, 20), (3, 30)]))
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* An empty list, e.g.::
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stmt.where(column.in_([]))
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In this calling form, the expression renders a "false" expression,
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e.g.::
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WHERE 1 != 1
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This "false" expression has historically had different behaviors
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in older SQLAlchemy versions, see
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:paramref:`.create_engine.empty_in_strategy` for behavioral options.
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.. versionchanged:: 1.2 simplified the behavior of "empty in"
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expressions
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* A bound parameter, e.g. :func:`.bindparam`, may be used if it
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includes the :paramref:`.bindparam.expanding` flag::
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stmt.where(column.in_(bindparam('value', expanding=True)))
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In this calling form, the expression renders a special non-SQL
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placeholder expression that looks like::
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WHERE COL IN ([EXPANDING_value])
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This placeholder expression is intercepted at statement execution
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time to be converted into the variable number of bound parameter
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form illustrated earlier. If the statement were executed as::
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connection.execute(stmt, {"value": [1, 2, 3]})
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The database would be passed a bound parameter for each value::
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WHERE COL IN (?, ?, ?)
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.. versionadded:: 1.2 added "expanding" bound parameters
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If an empty list is passed, a special "empty list" expression,
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which is specific to the database in use, is rendered. On
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SQLite this would be::
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WHERE COL IN (SELECT 1 FROM (SELECT 1) WHERE 1!=1)
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.. versionadded:: 1.3 "expanding" bound parameters now support
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empty lists
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* a :func:`.select` construct, which is usually a correlated
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scalar select::
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stmt.where(
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column.in_(
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select([othertable.c.y]).
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where(table.c.x == othertable.c.x)
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)
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)
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In this calling form, :meth:`.ColumnOperators.in_` renders as given::
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WHERE COL IN (SELECT othertable.y
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FROM othertable WHERE othertable.x = table.x)
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:param other: a list of literals, a :func:`.select` construct,
|
|
or a :func:`.bindparam` construct that includes the
|
|
:paramref:`.bindparam.expanding` flag set to True.
|
|
|
|
"""
|
|
return self.operate(in_op, other)
|
|
|
|
def notin_(self, other):
|
|
"""implement the ``NOT IN`` operator.
|
|
|
|
This is equivalent to using negation with
|
|
:meth:`.ColumnOperators.in_`, i.e. ``~x.in_(y)``.
|
|
|
|
In the case that ``other`` is an empty sequence, the compiler
|
|
produces an "empty not in" expression. This defaults to the
|
|
expression "1 = 1" to produce true in all cases. The
|
|
:paramref:`.create_engine.empty_in_strategy` may be used to
|
|
alter this behavior.
|
|
|
|
.. versionchanged:: 1.2 The :meth:`.ColumnOperators.in_` and
|
|
:meth:`.ColumnOperators.notin_` operators
|
|
now produce a "static" expression for an empty IN sequence
|
|
by default.
|
|
|
|
.. seealso::
|
|
|
|
:meth:`.ColumnOperators.in_`
|
|
|
|
"""
|
|
return self.operate(notin_op, other)
|
|
|
|
def notlike(self, other, escape=None):
|
|
"""implement the ``NOT LIKE`` operator.
|
|
|
|
This is equivalent to using negation with
|
|
:meth:`.ColumnOperators.like`, i.e. ``~x.like(y)``.
|
|
|
|
.. seealso::
|
|
|
|
:meth:`.ColumnOperators.like`
|
|
|
|
"""
|
|
return self.operate(notlike_op, other, escape=escape)
|
|
|
|
def notilike(self, other, escape=None):
|
|
"""implement the ``NOT ILIKE`` operator.
|
|
|
|
This is equivalent to using negation with
|
|
:meth:`.ColumnOperators.ilike`, i.e. ``~x.ilike(y)``.
|
|
|
|
.. seealso::
|
|
|
|
:meth:`.ColumnOperators.ilike`
|
|
|
|
"""
|
|
return self.operate(notilike_op, other, escape=escape)
|
|
|
|
def is_(self, other):
|
|
"""Implement the ``IS`` operator.
|
|
|
|
Normally, ``IS`` is generated automatically when comparing to a
|
|
value of ``None``, which resolves to ``NULL``. However, explicit
|
|
usage of ``IS`` may be desirable if comparing to boolean values
|
|
on certain platforms.
|
|
|
|
.. seealso:: :meth:`.ColumnOperators.isnot`
|
|
|
|
"""
|
|
return self.operate(is_, other)
|
|
|
|
def isnot(self, other):
|
|
"""Implement the ``IS NOT`` operator.
|
|
|
|
Normally, ``IS NOT`` is generated automatically when comparing to a
|
|
value of ``None``, which resolves to ``NULL``. However, explicit
|
|
usage of ``IS NOT`` may be desirable if comparing to boolean values
|
|
on certain platforms.
|
|
|
|
.. seealso:: :meth:`.ColumnOperators.is_`
|
|
|
|
"""
|
|
return self.operate(isnot, other)
|
|
|
|
def startswith(self, other, **kwargs):
|
|
r"""Implement the ``startswith`` operator.
|
|
|
|
Produces a LIKE expression that tests against a match for the start
|
|
of a string value::
|
|
|
|
column LIKE <other> || '%'
|
|
|
|
E.g.::
|
|
|
|
stmt = select([sometable]).\
|
|
where(sometable.c.column.startswith("foobar"))
|
|
|
|
Since the operator uses ``LIKE``, wildcard characters
|
|
``"%"`` and ``"_"`` that are present inside the <other> expression
|
|
will behave like wildcards as well. For literal string
|
|
values, the :paramref:`.ColumnOperators.startswith.autoescape` flag
|
|
may be set to ``True`` to apply escaping to occurrences of these
|
|
characters within the string value so that they match as themselves
|
|
and not as wildcard characters. Alternatively, the
|
|
:paramref:`.ColumnOperators.startswith.escape` parameter will establish
|
|
a given character as an escape character which can be of use when
|
|
the target expression is not a literal string.
|
|
|
|
:param other: expression to be compared. This is usually a plain
|
|
string value, but can also be an arbitrary SQL expression. LIKE
|
|
wildcard characters ``%`` and ``_`` are not escaped by default unless
|
|
the :paramref:`.ColumnOperators.startswith.autoescape` flag is
|
|
set to True.
|
|
|
|
:param autoescape: boolean; when True, establishes an escape character
|
|
within the LIKE expression, then applies it to all occurrences of
|
|
``"%"``, ``"_"`` and the escape character itself within the
|
|
comparison value, which is assumed to be a literal string and not a
|
|
SQL expression.
|
|
|
|
An expression such as::
|
|
|
|
somecolumn.startswith("foo%bar", autoescape=True)
|
|
|
|
Will render as::
|
|
|
|
somecolumn LIKE :param || '%' ESCAPE '/'
|
|
|
|
With the value of :param as ``"foo/%bar"``.
|
|
|
|
.. versionadded:: 1.2
|
|
|
|
.. versionchanged:: 1.2.0 The
|
|
:paramref:`.ColumnOperators.startswith.autoescape` parameter is
|
|
now a simple boolean rather than a character; the escape
|
|
character itself is also escaped, and defaults to a forwards
|
|
slash, which itself can be customized using the
|
|
:paramref:`.ColumnOperators.startswith.escape` parameter.
|
|
|
|
:param escape: a character which when given will render with the
|
|
``ESCAPE`` keyword to establish that character as the escape
|
|
character. This character can then be placed preceding occurrences
|
|
of ``%`` and ``_`` to allow them to act as themselves and not
|
|
wildcard characters.
|
|
|
|
An expression such as::
|
|
|
|
somecolumn.startswith("foo/%bar", escape="^")
|
|
|
|
Will render as::
|
|
|
|
somecolumn LIKE :param || '%' ESCAPE '^'
|
|
|
|
The parameter may also be combined with
|
|
:paramref:`.ColumnOperators.startswith.autoescape`::
|
|
|
|
somecolumn.startswith("foo%bar^bat", escape="^", autoescape=True)
|
|
|
|
Where above, the given literal parameter will be converted to
|
|
``"foo^%bar^^bat"`` before being passed to the database.
|
|
|
|
.. seealso::
|
|
|
|
:meth:`.ColumnOperators.endswith`
|
|
|
|
:meth:`.ColumnOperators.contains`
|
|
|
|
:meth:`.ColumnOperators.like`
|
|
|
|
"""
|
|
return self.operate(startswith_op, other, **kwargs)
|
|
|
|
def endswith(self, other, **kwargs):
|
|
r"""Implement the 'endswith' operator.
|
|
|
|
Produces a LIKE expression that tests against a match for the end
|
|
of a string value::
|
|
|
|
column LIKE '%' || <other>
|
|
|
|
E.g.::
|
|
|
|
stmt = select([sometable]).\
|
|
where(sometable.c.column.endswith("foobar"))
|
|
|
|
Since the operator uses ``LIKE``, wildcard characters
|
|
``"%"`` and ``"_"`` that are present inside the <other> expression
|
|
will behave like wildcards as well. For literal string
|
|
values, the :paramref:`.ColumnOperators.endswith.autoescape` flag
|
|
may be set to ``True`` to apply escaping to occurrences of these
|
|
characters within the string value so that they match as themselves
|
|
and not as wildcard characters. Alternatively, the
|
|
:paramref:`.ColumnOperators.endswith.escape` parameter will establish
|
|
a given character as an escape character which can be of use when
|
|
the target expression is not a literal string.
|
|
|
|
:param other: expression to be compared. This is usually a plain
|
|
string value, but can also be an arbitrary SQL expression. LIKE
|
|
wildcard characters ``%`` and ``_`` are not escaped by default unless
|
|
the :paramref:`.ColumnOperators.endswith.autoescape` flag is
|
|
set to True.
|
|
|
|
:param autoescape: boolean; when True, establishes an escape character
|
|
within the LIKE expression, then applies it to all occurrences of
|
|
``"%"``, ``"_"`` and the escape character itself within the
|
|
comparison value, which is assumed to be a literal string and not a
|
|
SQL expression.
|
|
|
|
An expression such as::
|
|
|
|
somecolumn.endswith("foo%bar", autoescape=True)
|
|
|
|
Will render as::
|
|
|
|
somecolumn LIKE '%' || :param ESCAPE '/'
|
|
|
|
With the value of :param as ``"foo/%bar"``.
|
|
|
|
.. versionadded:: 1.2
|
|
|
|
.. versionchanged:: 1.2.0 The
|
|
:paramref:`.ColumnOperators.endswith.autoescape` parameter is
|
|
now a simple boolean rather than a character; the escape
|
|
character itself is also escaped, and defaults to a forwards
|
|
slash, which itself can be customized using the
|
|
:paramref:`.ColumnOperators.endswith.escape` parameter.
|
|
|
|
:param escape: a character which when given will render with the
|
|
``ESCAPE`` keyword to establish that character as the escape
|
|
character. This character can then be placed preceding occurrences
|
|
of ``%`` and ``_`` to allow them to act as themselves and not
|
|
wildcard characters.
|
|
|
|
An expression such as::
|
|
|
|
somecolumn.endswith("foo/%bar", escape="^")
|
|
|
|
Will render as::
|
|
|
|
somecolumn LIKE '%' || :param ESCAPE '^'
|
|
|
|
The parameter may also be combined with
|
|
:paramref:`.ColumnOperators.endswith.autoescape`::
|
|
|
|
somecolumn.endswith("foo%bar^bat", escape="^", autoescape=True)
|
|
|
|
Where above, the given literal parameter will be converted to
|
|
``"foo^%bar^^bat"`` before being passed to the database.
|
|
|
|
.. seealso::
|
|
|
|
:meth:`.ColumnOperators.startswith`
|
|
|
|
:meth:`.ColumnOperators.contains`
|
|
|
|
:meth:`.ColumnOperators.like`
|
|
|
|
"""
|
|
return self.operate(endswith_op, other, **kwargs)
|
|
|
|
def contains(self, other, **kwargs):
|
|
r"""Implement the 'contains' operator.
|
|
|
|
Produces a LIKE expression that tests against a match for the middle
|
|
of a string value::
|
|
|
|
column LIKE '%' || <other> || '%'
|
|
|
|
E.g.::
|
|
|
|
stmt = select([sometable]).\
|
|
where(sometable.c.column.contains("foobar"))
|
|
|
|
Since the operator uses ``LIKE``, wildcard characters
|
|
``"%"`` and ``"_"`` that are present inside the <other> expression
|
|
will behave like wildcards as well. For literal string
|
|
values, the :paramref:`.ColumnOperators.contains.autoescape` flag
|
|
may be set to ``True`` to apply escaping to occurrences of these
|
|
characters within the string value so that they match as themselves
|
|
and not as wildcard characters. Alternatively, the
|
|
:paramref:`.ColumnOperators.contains.escape` parameter will establish
|
|
a given character as an escape character which can be of use when
|
|
the target expression is not a literal string.
|
|
|
|
:param other: expression to be compared. This is usually a plain
|
|
string value, but can also be an arbitrary SQL expression. LIKE
|
|
wildcard characters ``%`` and ``_`` are not escaped by default unless
|
|
the :paramref:`.ColumnOperators.contains.autoescape` flag is
|
|
set to True.
|
|
|
|
:param autoescape: boolean; when True, establishes an escape character
|
|
within the LIKE expression, then applies it to all occurrences of
|
|
``"%"``, ``"_"`` and the escape character itself within the
|
|
comparison value, which is assumed to be a literal string and not a
|
|
SQL expression.
|
|
|
|
An expression such as::
|
|
|
|
somecolumn.contains("foo%bar", autoescape=True)
|
|
|
|
Will render as::
|
|
|
|
somecolumn LIKE '%' || :param || '%' ESCAPE '/'
|
|
|
|
With the value of :param as ``"foo/%bar"``.
|
|
|
|
.. versionadded:: 1.2
|
|
|
|
.. versionchanged:: 1.2.0 The
|
|
:paramref:`.ColumnOperators.contains.autoescape` parameter is
|
|
now a simple boolean rather than a character; the escape
|
|
character itself is also escaped, and defaults to a forwards
|
|
slash, which itself can be customized using the
|
|
:paramref:`.ColumnOperators.contains.escape` parameter.
|
|
|
|
:param escape: a character which when given will render with the
|
|
``ESCAPE`` keyword to establish that character as the escape
|
|
character. This character can then be placed preceding occurrences
|
|
of ``%`` and ``_`` to allow them to act as themselves and not
|
|
wildcard characters.
|
|
|
|
An expression such as::
|
|
|
|
somecolumn.contains("foo/%bar", escape="^")
|
|
|
|
Will render as::
|
|
|
|
somecolumn LIKE '%' || :param || '%' ESCAPE '^'
|
|
|
|
The parameter may also be combined with
|
|
:paramref:`.ColumnOperators.contains.autoescape`::
|
|
|
|
somecolumn.contains("foo%bar^bat", escape="^", autoescape=True)
|
|
|
|
Where above, the given literal parameter will be converted to
|
|
``"foo^%bar^^bat"`` before being passed to the database.
|
|
|
|
.. seealso::
|
|
|
|
:meth:`.ColumnOperators.startswith`
|
|
|
|
:meth:`.ColumnOperators.endswith`
|
|
|
|
:meth:`.ColumnOperators.like`
|
|
|
|
|
|
"""
|
|
return self.operate(contains_op, other, **kwargs)
|
|
|
|
def match(self, other, **kwargs):
|
|
"""Implements a database-specific 'match' operator.
|
|
|
|
:meth:`~.ColumnOperators.match` attempts to resolve to
|
|
a MATCH-like function or operator provided by the backend.
|
|
Examples include:
|
|
|
|
* PostgreSQL - renders ``x @@ to_tsquery(y)``
|
|
* MySQL - renders ``MATCH (x) AGAINST (y IN BOOLEAN MODE)``
|
|
* Oracle - renders ``CONTAINS(x, y)``
|
|
* other backends may provide special implementations.
|
|
* Backends without any special implementation will emit
|
|
the operator as "MATCH". This is compatible with SQLite, for
|
|
example.
|
|
|
|
"""
|
|
return self.operate(match_op, other, **kwargs)
|
|
|
|
def desc(self):
|
|
"""Produce a :func:`~.expression.desc` clause against the
|
|
parent object."""
|
|
return self.operate(desc_op)
|
|
|
|
def asc(self):
|
|
"""Produce a :func:`~.expression.asc` clause against the
|
|
parent object."""
|
|
return self.operate(asc_op)
|
|
|
|
def nullsfirst(self):
|
|
"""Produce a :func:`~.expression.nullsfirst` clause against the
|
|
parent object."""
|
|
return self.operate(nullsfirst_op)
|
|
|
|
def nullslast(self):
|
|
"""Produce a :func:`~.expression.nullslast` clause against the
|
|
parent object."""
|
|
return self.operate(nullslast_op)
|
|
|
|
def collate(self, collation):
|
|
"""Produce a :func:`~.expression.collate` clause against
|
|
the parent object, given the collation string.
|
|
|
|
.. seealso::
|
|
|
|
:func:`~.expression.collate`
|
|
|
|
"""
|
|
return self.operate(collate, collation)
|
|
|
|
def __radd__(self, other):
|
|
"""Implement the ``+`` operator in reverse.
|
|
|
|
See :meth:`.ColumnOperators.__add__`.
|
|
|
|
"""
|
|
return self.reverse_operate(add, other)
|
|
|
|
def __rsub__(self, other):
|
|
"""Implement the ``-`` operator in reverse.
|
|
|
|
See :meth:`.ColumnOperators.__sub__`.
|
|
|
|
"""
|
|
return self.reverse_operate(sub, other)
|
|
|
|
def __rmul__(self, other):
|
|
"""Implement the ``*`` operator in reverse.
|
|
|
|
See :meth:`.ColumnOperators.__mul__`.
|
|
|
|
"""
|
|
return self.reverse_operate(mul, other)
|
|
|
|
def __rdiv__(self, other):
|
|
"""Implement the ``/`` operator in reverse.
|
|
|
|
See :meth:`.ColumnOperators.__div__`.
|
|
|
|
"""
|
|
return self.reverse_operate(div, other)
|
|
|
|
def __rmod__(self, other):
|
|
"""Implement the ``%`` operator in reverse.
|
|
|
|
See :meth:`.ColumnOperators.__mod__`.
|
|
|
|
"""
|
|
return self.reverse_operate(mod, other)
|
|
|
|
def between(self, cleft, cright, symmetric=False):
|
|
"""Produce a :func:`~.expression.between` clause against
|
|
the parent object, given the lower and upper range.
|
|
|
|
"""
|
|
return self.operate(between_op, cleft, cright, symmetric=symmetric)
|
|
|
|
def distinct(self):
|
|
"""Produce a :func:`~.expression.distinct` clause against the
|
|
parent object.
|
|
|
|
"""
|
|
return self.operate(distinct_op)
|
|
|
|
def any_(self):
|
|
"""Produce a :func:`~.expression.any_` clause against the
|
|
parent object.
|
|
|
|
This operator is only appropriate against a scalar subquery
|
|
object, or for some backends an column expression that is
|
|
against the ARRAY type, e.g.::
|
|
|
|
# postgresql '5 = ANY (somearray)'
|
|
expr = 5 == mytable.c.somearray.any_()
|
|
|
|
# mysql '5 = ANY (SELECT value FROM table)'
|
|
expr = 5 == select([table.c.value]).as_scalar().any_()
|
|
|
|
.. seealso::
|
|
|
|
:func:`~.expression.any_` - standalone version
|
|
|
|
:func:`~.expression.all_` - ALL operator
|
|
|
|
.. versionadded:: 1.1
|
|
|
|
"""
|
|
return self.operate(any_op)
|
|
|
|
def all_(self):
|
|
"""Produce a :func:`~.expression.all_` clause against the
|
|
parent object.
|
|
|
|
This operator is only appropriate against a scalar subquery
|
|
object, or for some backends an column expression that is
|
|
against the ARRAY type, e.g.::
|
|
|
|
# postgresql '5 = ALL (somearray)'
|
|
expr = 5 == mytable.c.somearray.all_()
|
|
|
|
# mysql '5 = ALL (SELECT value FROM table)'
|
|
expr = 5 == select([table.c.value]).as_scalar().all_()
|
|
|
|
.. seealso::
|
|
|
|
:func:`~.expression.all_` - standalone version
|
|
|
|
:func:`~.expression.any_` - ANY operator
|
|
|
|
.. versionadded:: 1.1
|
|
|
|
"""
|
|
return self.operate(all_op)
|
|
|
|
def __add__(self, other):
|
|
"""Implement the ``+`` operator.
|
|
|
|
In a column context, produces the clause ``a + b``
|
|
if the parent object has non-string affinity.
|
|
If the parent object has a string affinity,
|
|
produces the concatenation operator, ``a || b`` -
|
|
see :meth:`.ColumnOperators.concat`.
|
|
|
|
"""
|
|
return self.operate(add, other)
|
|
|
|
def __sub__(self, other):
|
|
"""Implement the ``-`` operator.
|
|
|
|
In a column context, produces the clause ``a - b``.
|
|
|
|
"""
|
|
return self.operate(sub, other)
|
|
|
|
def __mul__(self, other):
|
|
"""Implement the ``*`` operator.
|
|
|
|
In a column context, produces the clause ``a * b``.
|
|
|
|
"""
|
|
return self.operate(mul, other)
|
|
|
|
def __div__(self, other):
|
|
"""Implement the ``/`` operator.
|
|
|
|
In a column context, produces the clause ``a / b``.
|
|
|
|
"""
|
|
return self.operate(div, other)
|
|
|
|
def __mod__(self, other):
|
|
"""Implement the ``%`` operator.
|
|
|
|
In a column context, produces the clause ``a % b``.
|
|
|
|
"""
|
|
return self.operate(mod, other)
|
|
|
|
def __truediv__(self, other):
|
|
"""Implement the ``//`` operator.
|
|
|
|
In a column context, produces the clause ``a / b``.
|
|
|
|
"""
|
|
return self.operate(truediv, other)
|
|
|
|
def __rtruediv__(self, other):
|
|
"""Implement the ``//`` operator in reverse.
|
|
|
|
See :meth:`.ColumnOperators.__truediv__`.
|
|
|
|
"""
|
|
return self.reverse_operate(truediv, other)
|
|
|
|
|
|
_commutative = {eq, ne, add, mul}
|
|
_comparison = {eq, ne, lt, gt, ge, le}
|
|
|
|
|
|
def commutative_op(fn):
|
|
_commutative.add(fn)
|
|
return fn
|
|
|
|
|
|
def comparison_op(fn):
|
|
_comparison.add(fn)
|
|
return fn
|
|
|
|
|
|
def from_():
|
|
raise NotImplementedError()
|
|
|
|
|
|
@comparison_op
|
|
def function_as_comparison_op():
|
|
raise NotImplementedError()
|
|
|
|
|
|
def as_():
|
|
raise NotImplementedError()
|
|
|
|
|
|
def exists():
|
|
raise NotImplementedError()
|
|
|
|
|
|
def istrue(a):
|
|
raise NotImplementedError()
|
|
|
|
|
|
def isfalse(a):
|
|
raise NotImplementedError()
|
|
|
|
|
|
@comparison_op
|
|
def is_distinct_from(a, b):
|
|
return a.is_distinct_from(b)
|
|
|
|
|
|
@comparison_op
|
|
def isnot_distinct_from(a, b):
|
|
return a.isnot_distinct_from(b)
|
|
|
|
|
|
@comparison_op
|
|
def is_(a, b):
|
|
return a.is_(b)
|
|
|
|
|
|
@comparison_op
|
|
def isnot(a, b):
|
|
return a.isnot(b)
|
|
|
|
|
|
def collate(a, b):
|
|
return a.collate(b)
|
|
|
|
|
|
def op(a, opstring, b):
|
|
return a.op(opstring)(b)
|
|
|
|
|
|
@comparison_op
|
|
def like_op(a, b, escape=None):
|
|
return a.like(b, escape=escape)
|
|
|
|
|
|
@comparison_op
|
|
def notlike_op(a, b, escape=None):
|
|
return a.notlike(b, escape=escape)
|
|
|
|
|
|
@comparison_op
|
|
def ilike_op(a, b, escape=None):
|
|
return a.ilike(b, escape=escape)
|
|
|
|
|
|
@comparison_op
|
|
def notilike_op(a, b, escape=None):
|
|
return a.notilike(b, escape=escape)
|
|
|
|
|
|
@comparison_op
|
|
def between_op(a, b, c, symmetric=False):
|
|
return a.between(b, c, symmetric=symmetric)
|
|
|
|
|
|
@comparison_op
|
|
def notbetween_op(a, b, c, symmetric=False):
|
|
return a.notbetween(b, c, symmetric=symmetric)
|
|
|
|
|
|
@comparison_op
|
|
def in_op(a, b):
|
|
return a.in_(b)
|
|
|
|
|
|
@comparison_op
|
|
def notin_op(a, b):
|
|
return a.notin_(b)
|
|
|
|
|
|
def distinct_op(a):
|
|
return a.distinct()
|
|
|
|
|
|
def any_op(a):
|
|
return a.any_()
|
|
|
|
|
|
def all_op(a):
|
|
return a.all_()
|
|
|
|
|
|
def _escaped_like_impl(fn, other, escape, autoescape):
|
|
if autoescape:
|
|
if autoescape is not True:
|
|
util.warn(
|
|
"The autoescape parameter is now a simple boolean True/False"
|
|
)
|
|
if escape is None:
|
|
escape = "/"
|
|
|
|
if not isinstance(other, util.compat.string_types):
|
|
raise TypeError("String value expected when autoescape=True")
|
|
|
|
if escape not in ("%", "_"):
|
|
other = other.replace(escape, escape + escape)
|
|
|
|
other = other.replace("%", escape + "%").replace("_", escape + "_")
|
|
|
|
return fn(other, escape=escape)
|
|
|
|
|
|
@comparison_op
|
|
def startswith_op(a, b, escape=None, autoescape=False):
|
|
return _escaped_like_impl(a.startswith, b, escape, autoescape)
|
|
|
|
|
|
@comparison_op
|
|
def notstartswith_op(a, b, escape=None, autoescape=False):
|
|
return ~_escaped_like_impl(a.startswith, b, escape, autoescape)
|
|
|
|
|
|
@comparison_op
|
|
def endswith_op(a, b, escape=None, autoescape=False):
|
|
return _escaped_like_impl(a.endswith, b, escape, autoescape)
|
|
|
|
|
|
@comparison_op
|
|
def notendswith_op(a, b, escape=None, autoescape=False):
|
|
return ~_escaped_like_impl(a.endswith, b, escape, autoescape)
|
|
|
|
|
|
@comparison_op
|
|
def contains_op(a, b, escape=None, autoescape=False):
|
|
return _escaped_like_impl(a.contains, b, escape, autoescape)
|
|
|
|
|
|
@comparison_op
|
|
def notcontains_op(a, b, escape=None, autoescape=False):
|
|
return ~_escaped_like_impl(a.contains, b, escape, autoescape)
|
|
|
|
|
|
@comparison_op
|
|
def match_op(a, b, **kw):
|
|
return a.match(b, **kw)
|
|
|
|
|
|
@comparison_op
|
|
def notmatch_op(a, b, **kw):
|
|
return a.notmatch(b, **kw)
|
|
|
|
|
|
def comma_op(a, b):
|
|
raise NotImplementedError()
|
|
|
|
|
|
@comparison_op
|
|
def empty_in_op(a, b):
|
|
raise NotImplementedError()
|
|
|
|
|
|
@comparison_op
|
|
def empty_notin_op(a, b):
|
|
raise NotImplementedError()
|
|
|
|
|
|
def filter_op(a, b):
|
|
raise NotImplementedError()
|
|
|
|
|
|
def concat_op(a, b):
|
|
return a.concat(b)
|
|
|
|
|
|
def desc_op(a):
|
|
return a.desc()
|
|
|
|
|
|
def asc_op(a):
|
|
return a.asc()
|
|
|
|
|
|
def nullsfirst_op(a):
|
|
return a.nullsfirst()
|
|
|
|
|
|
def nullslast_op(a):
|
|
return a.nullslast()
|
|
|
|
|
|
def json_getitem_op(a, b):
|
|
raise NotImplementedError()
|
|
|
|
|
|
def json_path_getitem_op(a, b):
|
|
raise NotImplementedError()
|
|
|
|
|
|
def is_comparison(op):
|
|
return op in _comparison or isinstance(op, custom_op) and op.is_comparison
|
|
|
|
|
|
def is_commutative(op):
|
|
return op in _commutative
|
|
|
|
|
|
def is_ordering_modifier(op):
|
|
return op in (asc_op, desc_op, nullsfirst_op, nullslast_op)
|
|
|
|
|
|
def is_natural_self_precedent(op):
|
|
return (
|
|
op in _natural_self_precedent
|
|
or isinstance(op, custom_op)
|
|
and op.natural_self_precedent
|
|
)
|
|
|
|
|
|
_booleans = (inv, istrue, isfalse, and_, or_)
|
|
|
|
|
|
def is_boolean(op):
|
|
return is_comparison(op) or op in _booleans
|
|
|
|
|
|
_mirror = {gt: lt, ge: le, lt: gt, le: ge}
|
|
|
|
|
|
def mirror(op):
|
|
"""rotate a comparison operator 180 degrees.
|
|
|
|
Note this is not the same as negation.
|
|
|
|
"""
|
|
return _mirror.get(op, op)
|
|
|
|
|
|
_associative = _commutative.union([concat_op, and_, or_]).difference([eq, ne])
|
|
|
|
_natural_self_precedent = _associative.union(
|
|
[getitem, json_getitem_op, json_path_getitem_op]
|
|
)
|
|
"""Operators where if we have (a op b) op c, we don't want to
|
|
parenthesize (a op b).
|
|
|
|
"""
|
|
|
|
|
|
_asbool = util.symbol("_asbool", canonical=-10)
|
|
_smallest = util.symbol("_smallest", canonical=-100)
|
|
_largest = util.symbol("_largest", canonical=100)
|
|
|
|
_PRECEDENCE = {
|
|
from_: 15,
|
|
function_as_comparison_op: 15,
|
|
any_op: 15,
|
|
all_op: 15,
|
|
getitem: 15,
|
|
json_getitem_op: 15,
|
|
json_path_getitem_op: 15,
|
|
mul: 8,
|
|
truediv: 8,
|
|
div: 8,
|
|
mod: 8,
|
|
neg: 8,
|
|
add: 7,
|
|
sub: 7,
|
|
concat_op: 6,
|
|
filter_op: 6,
|
|
match_op: 5,
|
|
notmatch_op: 5,
|
|
ilike_op: 5,
|
|
notilike_op: 5,
|
|
like_op: 5,
|
|
notlike_op: 5,
|
|
in_op: 5,
|
|
notin_op: 5,
|
|
is_: 5,
|
|
isnot: 5,
|
|
eq: 5,
|
|
ne: 5,
|
|
is_distinct_from: 5,
|
|
isnot_distinct_from: 5,
|
|
empty_in_op: 5,
|
|
empty_notin_op: 5,
|
|
gt: 5,
|
|
lt: 5,
|
|
ge: 5,
|
|
le: 5,
|
|
between_op: 5,
|
|
notbetween_op: 5,
|
|
distinct_op: 5,
|
|
inv: 5,
|
|
istrue: 5,
|
|
isfalse: 5,
|
|
and_: 3,
|
|
or_: 2,
|
|
comma_op: -1,
|
|
desc_op: 3,
|
|
asc_op: 3,
|
|
collate: 4,
|
|
as_: -1,
|
|
exists: 0,
|
|
_asbool: -10,
|
|
_smallest: _smallest,
|
|
_largest: _largest,
|
|
}
|
|
|
|
|
|
def is_precedent(operator, against):
|
|
if operator is against and is_natural_self_precedent(operator):
|
|
return False
|
|
else:
|
|
return _PRECEDENCE.get(
|
|
operator, getattr(operator, "precedence", _smallest)
|
|
) <= _PRECEDENCE.get(against, getattr(against, "precedence", _largest))
|