- The MySQL CAST compilation now takes into account aspects of a string

type such as "charset" and "collation".  While MySQL wants all character-
based CAST calls to use the CHAR type, we now create a real CHAR
object at CAST time and copy over all the parameters it has, so that
an expression like ``cast(x, mysql.TEXT(charset='utf8'))`` will
render ``CAST(t.col AS CHAR CHARACTER SET utf8)``.

- Added new "unicode returns" detection to the MySQL dialect and
to the default dialect system overall, such that any dialect
can add extra "tests" to the on-first-connect "does this DBAPI
return unicode directly?" detection. In this case, we are
adding a check specifically against the "utf8" encoding with
an explicit "utf8_bin" collation type (after checking that
this collation is available) to test for some buggy unicode
behavior observed with MySQLdb version 1.2.3.  While MySQLdb
has resolved this issue as of 1.2.4, the check here should
guard against regressions.  The change also allows the "unicode"
checks to log in the engine logs, which was not previously
the case. [ticket:2906]

2 files changed, 12 insertions, 2 deletions

diff --git a/test/dialect/mysql/test_compiler.py b/test/dialect/mysql/test_compiler.py
index 46e8bfb82..45f8405c8 100644
--- a/test/dialect/mysql/test_compiler.py
+++ b/test/dialect/mysql/test_compiler.py
@@ -341,8 +341,10 @@ class SQLTest(fixtures.TestBase, AssertsCompiledSQL):
             (VARCHAR, "CAST(t.col AS CHAR)"),
             (NCHAR, "CAST(t.col AS CHAR)"),
             (CHAR, "CAST(t.col AS CHAR)"),
+            (m.CHAR(charset='utf8'), "CAST(t.col AS CHAR CHARACTER SET utf8)"),
             (CLOB, "CAST(t.col AS CHAR)"),
             (TEXT, "CAST(t.col AS CHAR)"),
+            (m.TEXT(charset='utf8'), "CAST(t.col AS CHAR CHARACTER SET utf8)"),
             (String(32), "CAST(t.col AS CHAR(32))"),
             (Unicode(32), "CAST(t.col AS CHAR(32))"),
             (CHAR(32), "CAST(t.col AS CHAR(32))"),
diff --git a/test/dialect/mysql/test_types.py b/test/dialect/mysql/test_types.py
index e3d5d6185..acf9c1e2f 100644
--- a/test/dialect/mysql/test_types.py
+++ b/test/dialect/mysql/test_types.py
@@ -264,15 +264,23 @@ class TypesTest(fixtures.TestBase, AssertsExecutionResults, AssertsCompiledSQL):
     def test_charset_collate_table(self):
         t = Table('foo', self.metadata,
             Column('id', Integer),
+            Column('data', UnicodeText),
             mysql_default_charset='utf8',
-            mysql_collate='utf8_unicode_ci'
+            mysql_collate='utf8_bin'
         )
         t.create()
         m2 = MetaData(testing.db)
         t2 = Table('foo', m2, autoload=True)
-        eq_(t2.kwargs['mysql_collate'], 'utf8_unicode_ci')
+        eq_(t2.kwargs['mysql_collate'], 'utf8_bin')
         eq_(t2.kwargs['mysql_default charset'], 'utf8')
 
+        # test [ticket:2906]
+        # in order to test the condition here, need to use
+        # MySQLdb 1.2.3 and also need to pass either use_unicode=1
+        # or charset=utf8 to the URL.
+        t.insert().execute(id=1, data=u('some text'))
+        assert isinstance(testing.db.scalar(select([t.c.data])), util.text_type)
+
     def test_bit_50(self):
         """Exercise BIT types on 5.0+ (not valid for all engine types)"""