Work around (apparent) Python bug for issue #206

It looks like PyCodec_Encode can set an extraneous exception even when it works.  (It should
return 0 if it fails.)  This causes Cursor.fetchall() to fail since it looks for exceptions.

Fixes #206

src/textenc.cpp

@@ -13,7 +13,23 @@ PyObject* TextEnc::Encode(PyObject* obj) const
     }
 #endif
 
-    return PyCodec_Encode(obj, name, "strict");
+    PyObject* bytes = PyCodec_Encode(obj, name, "strict");
+
+    if (bytes && PyErr_Occurred())
+    {
+        // REVIEW: Issue #206.  I am not sure what is going on here, but PyCodec_Encode
+        // sometimes returns bytes but *also* sets an exception saying "'ascii' codec can't
+        // encode characters...".  I assume the ascii is from my sys encoding, but it seems to
+        // be a superflous error.  Since Cursor.fetchall() looks for exceptions this extraneous
+        // error causes us to throw an exception.
+        //
+        // I'm putting in a work around but we should track down the root cause and report it
+        // to the Python project if it is not ours.
+
+        PyErr_Clear();
+    }
+
+    return bytes;
 }
 
 

tests2/sqlservertests.py

@@ -627,6 +627,23 @@ def test_empty_unicode_encoding(self):
     def test_unicode_query(self):
         self.cursor.execute(u"select 1")
 
+    # From issue #206
+    def _maketest(value):
+        def t(self):
+            self._test_strtype('nvarchar', value, colsize=len(value))
+        return t
+    locals()['test_chinese_param'] = _maketest(u'我的')
+
+    def test_chinese(self):
+        v = u'我的'
+        self.cursor.execute(u"SELECT N'我的' AS [Name]")
+        row = self.cursor.fetchone()
+        self.assertEqual(row[0], v)
+
+        self.cursor.execute(u"SELECT N'我的' AS [Name]")
+        rows = self.cursor.fetchall()
+        self.assertEqual(rows[0][0], v)
+
     def test_negative_row_index(self):
         self.cursor.execute("create table t1(s varchar(20))")
         self.cursor.execute("insert into t1 values(?)", "1")

tests3/sqlservertests.py

@@ -1,5 +1,5 @@
 #!/usr/bin/python
-# -*- coding: latin-1 -*-
+# -*- coding: utf-8 -*-
 
 x = 1 # Getting an error if starting with usage for some reason.
 
@@ -82,7 +82,6 @@ def setUp(self):
         # different collation, you'll need to update this.  If someone knows of
         # a good way for this to be dynamic, please update.  (I suppose we
         # could maintain a map from collation to encoding?)
-        self.cnxn.setencoding('latin1')
         self.cnxn.setdecoding(pyodbc.SQL_CHAR, 'latin1')
 
         for i in range(3):
@@ -317,7 +316,7 @@ def test_varchar_many(self):
         self.assertEqual(v3, row.c3)
 
     #
-    # unicode
+    # nvarchar
     #
 
     def test_unicode_null(self):
@@ -339,6 +338,24 @@ def test_unicode_longmax(self):
             return              # so pass / ignore
         self.cursor.execute("select cast(replicate(N'x', 512) as nvarchar(max))")
 
+    # From issue #206
+    def _maketest(value):
+        def t(self):
+            self._test_strtype('nvarchar', value, colsize=len(value))
+        return t
+    locals()['test_chinese_param'] = _maketest('我的')
+
+    def test_chinese(self):
+        v = '我的'
+        self.cursor.execute(u"SELECT N'我的' AS [Name]")
+        row = self.cursor.fetchone()
+        self.assertEqual(row[0], v)
+
+        self.cursor.execute(u"SELECT N'我的' AS [Name]")
+        rows = self.cursor.fetchall()
+        self.assertEqual(rows[0][0], v)
+
+
     #
     # binary
     #
@@ -1337,8 +1354,8 @@ def test_decode_meta(self):
         # This is from GitHub issue #190
         self.cursor.execute("create table t1(a int)")
         self.cursor.execute("insert into t1 values (1)")
-        self.cursor.execute('select a as "Tipología" from t1')
-        self.assertEqual(self.cursor.description[0][0], "Tipología")
+        self.cursor.execute('select a as "Tipología" from t1')
+        self.assertEqual(self.cursor.description[0][0], "Tipología")
 
 
 def main():