- postgres cursor option is now server_side_cursors=False; some users get bad results using them

so theyre off by default
- type system slightly modified to support TypeDecorators that can be overridden by the dialect
- added an NVarchar type to mssql (produces NVARCHAR), also MSUnicode which provides Unicode-translation
for the NVarchar regardless of dialect convert_unicode setting.

3 files changed, 20 insertions, 12 deletions

diff --git a/lib/sqlalchemy/databases/mssql.py b/lib/sqlalchemy/databases/mssql.py
index 2028ab48f..6d351d0fb 100644
--- a/lib/sqlalchemy/databases/mssql.py
+++ b/lib/sqlalchemy/databases/mssql.py
@@ -146,9 +146,13 @@ class MSText(sqltypes.TEXT):
 class MSString(sqltypes.String):
     def get_col_spec(self):
         return "VARCHAR(%(length)s)" % {'length' : self.length}
-class MSUnicode(sqltypes.Unicode):
+class MSNVarchar(MSString):
+    """NVARCHAR string, does unicode conversion if dialect.convert_encoding is true"""
     def get_col_spec(self):
         return "NVARCHAR(%(length)s)" % {'length' : self.length}
+class MSUnicode(sqltypes.Unicode):
+    """Unicode subclass, does unicode conversion in all cases, uses NVARCHAR impl"""
+    impl = MSNVarchar
 class MSChar(sqltypes.CHAR):
     def get_col_spec(self):
         return "CHAR(%(length)s)" % {'length' : self.length}
@@ -259,8 +263,6 @@ class MSSQLExecutionContext(default.DefaultExecutionContext):
             self.HASIDENT = False
 
 
-
-
 class MSSQLDialect(ansisql.ANSIDialect):
     def __init__(self, module=None, auto_identity_insert=False, **params):
         self.module = module or dbmodule
@@ -546,7 +548,7 @@ class MSSQLCompiler(ansisql.ANSICompiler):
 class MSSQLSchemaGenerator(ansisql.ANSISchemaGenerator):
     def get_column_specification(self, column, **kwargs):
         colspec = self.preparer.format_column(column) + " " + column.type.engine_impl(self.engine).get_col_spec()
-
+        
         # install a IDENTITY Sequence if we have an implicit IDENTITY column
         if column.primary_key and column.autoincrement and isinstance(column.type, sqltypes.Integer) and not column.foreign_key:
             if column.default is None or (isinstance(column.default, schema.Sequence) and column.default.optional):
@@ -583,7 +585,7 @@ class MSSQLIdentifierPreparer(ansisql.ANSIIdentifierPreparer):
         #TODO: determin MSSQL's case folding rules
         return value
 
-if dbmodule.__name__ == 'adodbapi':
+if dbmodule and dbmodule.__name__ == 'adodbapi':
 	dialect = MSSQLDialect
 else:
 	dialect = PyMSSQLDialect
diff --git a/lib/sqlalchemy/databases/postgres.py b/lib/sqlalchemy/databases/postgres.py
index 79db8716c..94519a5ac 100644
--- a/lib/sqlalchemy/databases/postgres.py
+++ b/lib/sqlalchemy/databases/postgres.py
@@ -207,9 +207,9 @@ class PGExecutionContext(default.DefaultExecutionContext):
                 self._last_inserted_ids = [v for v in row]
     
 class PGDialect(ansisql.ANSIDialect):
-    def __init__(self, module=None, use_oids=False, use_information_schema=False, client_side_cursors=False, **params):
+    def __init__(self, module=None, use_oids=False, use_information_schema=False, server_side_cursors=False, **params):
         self.use_oids = use_oids
-        self.client_side_cursors = client_side_cursors
+        self.server_side_cursors = server_side_cursors
         if module is None:
             #if psycopg is None:
             #    raise exceptions.ArgumentError("Couldnt locate psycopg1 or psycopg2: specify postgres module argument")
@@ -241,13 +241,12 @@ class PGDialect(ansisql.ANSIDialect):
         return ([], opts)
 
     def create_cursor(self, connection):
-        if self.client_side_cursors:
-            return connection.cursor()
-        else:
+        if self.server_side_cursors:
             # use server-side cursors:
             # http://lists.initd.org/pipermail/psycopg/2007-January/005251.html
             return connection.cursor('x')
-
+        else:
+            return connection.cursor()
 
     def create_execution_context(self):
         return PGExecutionContext(self)
diff --git a/lib/sqlalchemy/types.py b/lib/sqlalchemy/types.py
index 336231242..726044270 100644
--- a/lib/sqlalchemy/types.py
+++ b/lib/sqlalchemy/types.py
@@ -82,6 +82,12 @@ class TypeDecorator(AbstractType):
         try:
             return self.impl_dict[dialect]
         except:
+            # see if the dialect has an adaptation of the TypeDecorator itself
+            adapted_decorator = dialect.type_descriptor(self)
+            if adapted_decorator is not self:
+                result = adapted_decorator.dialect_impl(dialect)
+                self.impl_dict[dialect] = result
+                return result
             typedesc = dialect.type_descriptor(self.impl)
             tt = self.copy()
             if not isinstance(tt, self.__class__):
@@ -138,7 +144,8 @@ def adapt_type(typeobj, colspecs):
         except KeyError:
             pass
     else:
-        # couldnt adapt...raise exception ?
+        # couldnt adapt - so just return the type itself
+        # (it may be a user-defined type)
         return typeobj
     # if we adapted the given generic type to a database-specific type, 
     # but it turns out the originally given "generic" type