diff options
Diffstat (limited to 'lib/sqlalchemy/sql')
| -rw-r--r-- | lib/sqlalchemy/sql/sqltypes.py | 41 |
1 files changed, 37 insertions, 4 deletions
diff --git a/lib/sqlalchemy/sql/sqltypes.py b/lib/sqlalchemy/sql/sqltypes.py index 061f8de96..2a30bf832 100644 --- a/lib/sqlalchemy/sql/sqltypes.py +++ b/lib/sqlalchemy/sql/sqltypes.py @@ -1581,9 +1581,22 @@ class Boolean(Emulated, TypeEngine, SchemaType): """A bool datatype. - Boolean typically uses BOOLEAN or SMALLINT on the DDL side, and on + :class:`.Boolean` typically uses BOOLEAN or SMALLINT on the DDL side, and on the Python side deals in ``True`` or ``False``. + The :class:`.Boolean` datatype currently has two levels of assertion + that the values persisted are simple true/false values. For all + backends, only the Python values ``None``, ``True``, ``False``, ``1`` + or ``0`` are accepted as parameter values. For those backends that + don't support a "native boolean" datatype, a CHECK constraint is also + created on the target column. Production of the CHECK constraint + can be disabled by passing the :paramref:`.Boolean.create_constraint` + flag set to ``False``. + + .. versionchanged:: 1.2 the :class:`.Boolean` datatype now asserts that + incoming Python values are already in pure boolean form. + + """ __visit_name__ = 'boolean' @@ -1631,20 +1644,40 @@ class Boolean(Emulated, TypeEngine, SchemaType): def python_type(self): return bool + _strict_bools = frozenset([None, True, False]) + + def _strict_as_bool(self, value): + if value not in self._strict_bools: + if not isinstance(value, int): + raise TypeError( + "Not a boolean value: %r" % value) + else: + raise ValueError( + "Value %r is not None, True, or False" % value) + return value + def literal_processor(self, dialect): compiler = dialect.statement_compiler(dialect, None) true = compiler.visit_true(None) false = compiler.visit_false(None) def process(value): - return true if value else false + return true if self._strict_as_bool(value) else false return process def bind_processor(self, dialect): + _strict_as_bool = self._strict_as_bool if dialect.supports_native_boolean: - return None + _coerce = bool else: - return processors.boolean_to_int + _coerce = int + + def process(value): + value = _strict_as_bool(value) + if value is not None: + value = _coerce(value) + return value + return process def result_processor(self, dialect, coltype): if dialect.supports_native_boolean: |