diff options
Diffstat (limited to 'lib/sqlalchemy/sql/operators.py')
| -rw-r--r-- | lib/sqlalchemy/sql/operators.py | 21 |
1 files changed, 17 insertions, 4 deletions
diff --git a/lib/sqlalchemy/sql/operators.py b/lib/sqlalchemy/sql/operators.py index d7ec977aa..91301c78c 100644 --- a/lib/sqlalchemy/sql/operators.py +++ b/lib/sqlalchemy/sql/operators.py @@ -102,7 +102,7 @@ class Operators(object): """ return self.operate(inv) - def op(self, opstring, precedence=0): + def op(self, opstring, precedence=0, is_comparison=False): """produce a generic operator function. e.g.:: @@ -134,12 +134,23 @@ class Operators(object): .. versionadded:: 0.8 - added the 'precedence' argument. + :param is_comparison: if True, the operator will be considered as a + "comparison" operator, that is which evaulates to a boolean true/false + value, like ``==``, ``>``, etc. This flag should be set so that + ORM relationships can establish that the operator is a comparison + operator when used in a custom join condition. + + .. versionadded:: 0.9.2 - added the :paramref:`.Operators.op.is_comparison` + flag. + .. seealso:: :ref:`types_operators` + :ref:`relationship_custom_operator` + """ - operator = custom_op(opstring, precedence) + operator = custom_op(opstring, precedence, is_comparison) def against(other): return operator(self, other) @@ -200,9 +211,10 @@ class custom_op(object): """ __name__ = 'custom_op' - def __init__(self, opstring, precedence=0): + def __init__(self, opstring, precedence=0, is_comparison=False): self.opstring = opstring self.precedence = precedence + self.is_comparison = is_comparison def __eq__(self, other): return isinstance(other, custom_op) and \ @@ -769,7 +781,8 @@ _comparison = set([eq, ne, lt, gt, ge, le, between_op]) def is_comparison(op): - return op in _comparison + return op in _comparison or \ + isinstance(op, custom_op) and op.is_comparison def is_commutative(op): |