- Added new checks for the common error case of passing mapped classes

or mapped instances into contexts where they are interpreted as
SQL bound parameters; a new exception is raised for this.
fixes #3321

5 files changed, 25 insertions, 10 deletions

diff --git a/lib/sqlalchemy/sql/compiler.py b/lib/sqlalchemy/sql/compiler.py
index d3c46e643..4717b777f 100644
--- a/lib/sqlalchemy/sql/compiler.py
+++ b/lib/sqlalchemy/sql/compiler.py
@@ -281,6 +281,8 @@ class _CompileLabel(visitors.Visitable):
     def type(self):
         return self.element.type
 
+    def self_group(self, **kw):
+        return self
 
 class SQLCompiler(Compiled):
 
diff --git a/lib/sqlalchemy/sql/default_comparator.py b/lib/sqlalchemy/sql/default_comparator.py
index 09f639163..125fec33f 100644
--- a/lib/sqlalchemy/sql/default_comparator.py
+++ b/lib/sqlalchemy/sql/default_comparator.py
@@ -15,7 +15,7 @@ from .elements import BindParameter, True_, False_, BinaryExpression, \
     Null, _const_expr, _clause_element_as_expr, \
     ClauseList, ColumnElement, TextClause, UnaryExpression, \
     collate, _is_literal, _literal_as_text, ClauseElement, and_, or_, \
-    Slice
+    Slice, Visitable
 from .selectable import SelectBase, Alias, Selectable, ScalarSelect
 
 
@@ -304,7 +304,7 @@ def _check_literal(expr, operator, other):
 
     if isinstance(other, (SelectBase, Alias)):
         return other.as_scalar()
-    elif not isinstance(other, (ColumnElement, TextClause)):
+    elif not isinstance(other, Visitable):
         return expr._bind_param(operator, other)
     else:
         return other
diff --git a/lib/sqlalchemy/sql/elements.py b/lib/sqlalchemy/sql/elements.py
index 00c749b40..e2d81afc1 100644
--- a/lib/sqlalchemy/sql/elements.py
+++ b/lib/sqlalchemy/sql/elements.py
@@ -1145,8 +1145,7 @@ class BindParameter(ColumnElement):
                     _compared_to_type.coerce_compared_value(
                         _compared_to_operator, value)
             else:
-                self.type = type_api._type_map.get(type(value),
-                                                   type_api.NULLTYPE)
+                self.type = type_api._resolve_value_to_type(value)
         elif isinstance(type_, type):
             self.type = type_()
         else:
@@ -1161,8 +1160,7 @@ class BindParameter(ColumnElement):
         cloned.callable = None
         cloned.required = False
         if cloned.type is type_api.NULLTYPE:
-            cloned.type = type_api._type_map.get(type(value),
-                                                 type_api.NULLTYPE)
+            cloned.type = type_api._resolve_value_to_type(value)
         return cloned
 
     @property
diff --git a/lib/sqlalchemy/sql/sqltypes.py b/lib/sqlalchemy/sql/sqltypes.py
index ec7dea300..b5c575143 100644
--- a/lib/sqlalchemy/sql/sqltypes.py
+++ b/lib/sqlalchemy/sql/sqltypes.py
@@ -9,7 +9,6 @@
 
 """
 
-import collections
 import datetime as dt
 import codecs
 
@@ -18,6 +17,7 @@ from .elements import quoted_name, type_coerce, _defer_name
 from .. import exc, util, processors
 from .base import _bind_or_error, SchemaEventTarget
 from . import operators
+from .. import inspection
 from .. import event
 from ..util import pickle
 import decimal
@@ -1736,6 +1736,21 @@ else:
     _type_map[unicode] = Unicode()
     _type_map[str] = String()
 
+_type_map_get = _type_map.get
+
+
+def _resolve_value_to_type(value):
+    _result_type = _type_map_get(type(value), False)
+    if _result_type is False:
+        # use inspect() to detect SQLAlchemy built-in
+        # objects.
+        insp = inspection.inspect(value, False)
+        if insp is not None:
+            raise exc.ArgumentError(
+                "Object %r is not legal as a SQL literal value" % value)
+        return NULLTYPE
+    else:
+        return _result_type
 
 # back-assign to type_api
 from . import type_api
@@ -1745,6 +1760,5 @@ type_api.INTEGERTYPE = INTEGERTYPE
 type_api.NULLTYPE = NULLTYPE
 type_api.MATCHTYPE = MATCHTYPE
 type_api.INDEXABLE = Indexable
-type_api._type_map = _type_map
-
+type_api._resolve_value_to_type = _resolve_value_to_type
 TypeEngine.Comparator.BOOLEANTYPE = BOOLEANTYPE
diff --git a/lib/sqlalchemy/sql/type_api.py b/lib/sqlalchemy/sql/type_api.py
index c4e830b7f..b9826e585 100644
--- a/lib/sqlalchemy/sql/type_api.py
+++ b/lib/sqlalchemy/sql/type_api.py
@@ -21,6 +21,7 @@ NULLTYPE = None
 STRINGTYPE = None
 MATCHTYPE = None
 INDEXABLE = None
+_resolve_value_to_type = None
 
 
 class TypeEngine(Visitable):
@@ -454,7 +455,7 @@ class TypeEngine(Visitable):
         end-user customization of this behavior.
 
         """
-        _coerced_type = _type_map.get(type(value), NULLTYPE)
+        _coerced_type = _resolve_value_to_type(value)
         if _coerced_type is NULLTYPE or _coerced_type._type_affinity \
                 is self._type_affinity:
             return self