diff options
Diffstat (limited to 'lib/sqlalchemy/sql.py')
| -rw-r--r-- | lib/sqlalchemy/sql.py | 34 |
1 files changed, 22 insertions, 12 deletions
diff --git a/lib/sqlalchemy/sql.py b/lib/sqlalchemy/sql.py index 1f3d3575e..1a732742d 100644 --- a/lib/sqlalchemy/sql.py +++ b/lib/sqlalchemy/sql.py @@ -122,8 +122,7 @@ def or_(*clauses): def not_(clause): """returns a negation of the given clause, i.e. NOT(clause). the ~ operator can be used as well.""" - clause.parens=True - return BooleanExpression(TextClause("NOT"), clause, None) + return clause._negate() def between(ctest, cleft, cright): """ returns BETWEEN predicate clause (clausetest BETWEEN clauseleft AND clauseright). @@ -527,7 +526,10 @@ class ClauseElement(object): def __or__(self, other): return or_(self, other) def __invert__(self): - return not_(self) + return self._negate() + def _negate(self): + self.parens=True + return BooleanExpression(TextClause("NOT"), self, None) class CompareMixin(object): """defines comparison operations for ClauseElements.""" @@ -551,12 +553,12 @@ class CompareMixin(object): elif len(other) == 1 and not hasattr(other[0], '_selectable'): return self.__eq__(other[0]) elif _is_literal(other[0]): - return self._compare('IN', ClauseList(parens=True, *[self._bind_param(o) for o in other])) + return self._compare('IN', ClauseList(parens=True, *[self._bind_param(o) for o in other]), negate='NOT IN') else: # assume *other is a list of selects. # so put them in a UNION. if theres only one, you just get one SELECT # statement out of it. - return self._compare('IN', union(parens=True, *other)) + return self._compare('IN', union(parens=True, *other), negate='NOT IN') def startswith(self, other): return self._compare('LIKE', other + "%") def endswith(self, other): @@ -589,18 +591,18 @@ class CompareMixin(object): return self._bind_param(other) else: return other - def _compare(self, operator, obj): + def _compare(self, operator, obj, negate=None): if obj is None or isinstance(obj, Null): if operator == '=': - return BooleanExpression(self._compare_self(), null(), 'IS') + return BooleanExpression(self._compare_self(), null(), 'IS', negate='IS NOT') elif operator == '!=': - return BooleanExpression(self._compare_self(), null(), 'IS NOT') + return BooleanExpression(self._compare_self(), null(), 'IS NOT', negate='IS') else: raise exceptions.ArgumentError("Only '='/'!=' operators can be used with NULL") else: obj = self._check_literal(obj) - return BooleanExpression(self._compare_self(), obj, operator, type=self._compare_type(obj)) + return BooleanExpression(self._compare_self(), obj, operator, type=self._compare_type(obj), negate=negate) def _operate(self, operator, obj): if _is_literal(obj): obj = self._bind_param(obj) @@ -613,7 +615,7 @@ class CompareMixin(object): """allows subclasses to override the type used in constructing BinaryClause objects. Default return value is the type of the given object.""" return obj.type - + class Selectable(ClauseElement): """represents a column list-holding object.""" @@ -1028,7 +1030,7 @@ class BinaryClause(ClauseElement): if isinstance(self.right, BinaryClause) or hasattr(self.right, '_selectable'): self.right.parens = True def copy_container(self): - return BinaryClause(self.left.copy_container(), self.right.copy_container(), self.operator) + return self.__class__(self.left.copy_container(), self.right.copy_container(), self.operator) def _get_from_objects(self): return self.left._get_from_objects() + self.right._get_from_objects() def accept_visitor(self, visitor): @@ -1048,7 +1050,15 @@ class BinaryClause(ClauseElement): class BooleanExpression(BinaryClause): """represents a boolean expression, which is only useable in WHERE criterion.""" - pass + def __init__(self, *args, **kwargs): + self.negate = kwargs.pop('negate', None) + super(BooleanExpression, self).__init__(*args, **kwargs) + def _negate(self): + if self.negate is not None: + return BooleanExpression(self.left, self.right, self.negate, negate=self.operator, type=self.type) + else: + return super(BooleanExpression, self)._negate() + class BinaryExpression(BinaryClause, ColumnElement): """represents a binary expression, which can be in a WHERE criterion or in the column list of a SELECT. By adding "ColumnElement" to its inherited list, it becomes a Selectable |