Fix TypeError during cx_Oracle connectionpr/271

cx_Oracle connection parameters user, password and dsn must be
either a string or NULL.  When they are passed a Python None object,
"TypeError: expecting string, unicode or buffer object" is raised.

1 files changed, 7 insertions, 3 deletions

diff --git a/lib/sqlalchemy/dialects/oracle/cx_oracle.py b/lib/sqlalchemy/dialects/oracle/cx_oracle.py
index dede3b21a..dfceb3091 100644
--- a/lib/sqlalchemy/dialects/oracle/cx_oracle.py
+++ b/lib/sqlalchemy/dialects/oracle/cx_oracle.py
@@ -898,13 +898,17 @@ class OracleDialect_cx_oracle(OracleDialect):
             dsn = url.host
 
         opts = dict(
-            user=url.username,
-            password=url.password,
-            dsn=dsn,
             threaded=self.threaded,
             twophase=self.allow_twophase,
         )
 
+        if dsn is not None:
+            opts['dsn'] = dsn
+        if url.password is not None:
+            opts['password'] = url.password
+        if url.username is not None:
+            opts['user'] = url.username
+
         if util.py2k:
             if self._cx_oracle_with_unicode:
                 for k, v in opts.items():