[Sqlalchemy-tickets] Issue #3337: pymysql unicode expects unicode or non-unicode for statement/binds at the same time (zzzeek/sqlalchemy)

[Mike B. <iss...@bi...>]

New issue 3337: pymysql unicode expects unicode or non-unicode for statement/binds at the same time
https://bitbucket.org/zzzeek/sqlalchemy/issue/3337/pymysql-unicode-expects-unicode-or-non

Mike Bayer:

we can set supports_unicode_statements and supports_unicode_binds to True or False and PyMySQL tests pass from 0.4 to 0.6.6.  However, if statements is True and binds is False as it is right now, then the "executemany" tests fail, b.c. pymysql is generally using string interpolation to produce the string.  Stack is as follows:


```
#!

$ python -m pytest test/dialect/test_suite.py --dburi "mysql+pymysql://scott:tiger@localhost/test?charset=utf8" -k UnicodeVarcharTest 
===================================================================== test session starts ======================================================================
platform darwin -- Python 2.7.5 -- py-1.4.26 -- pytest-2.6.4 -- /Library/Frameworks/Python.framework/Versions/2.7/Resources/Python.app/Contents/MacOS/Python
plugins: cov, xdist
collected 143 items 

test/dialect/test_suite.py <- lib/sqlalchemy/testing/suite/test_types.py::UnicodeVarcharTest_mysql_pymysql::test_empty_strings_varchar PASSED
test/dialect/test_suite.py <- lib/sqlalchemy/testing/suite/test_types.py::UnicodeVarcharTest_mysql_pymysql::test_literal PASSED
test/dialect/test_suite.py <- lib/sqlalchemy/testing/suite/test_types.py::UnicodeVarcharTest_mysql_pymysql::test_round_trip PASSED
test/dialect/test_suite.py <- lib/sqlalchemy/testing/suite/test_types.py::UnicodeVarcharTest_mysql_pymysql::test_round_trip_executemany FAILED

=========================================================================== FAILURES ===========================================================================
_________________________________________________ UnicodeVarcharTest_mysql_pymysql.test_round_trip_executemany _________________________________________________
Traceback (most recent call last):
  File "/Users/classic/dev/sqlalchemy/lib/sqlalchemy/testing/suite/test_types.py", line 89, in test_round_trip_executemany
    for i in range(3)
  File "/Users/classic/dev/sqlalchemy/lib/sqlalchemy/engine/base.py", line 1978, in execute
    return connection.execute(statement, *multiparams, **params)
  File "/Users/classic/dev/sqlalchemy/lib/sqlalchemy/engine/base.py", line 914, in execute
    return meth(self, multiparams, params)
  File "/Users/classic/dev/sqlalchemy/lib/sqlalchemy/sql/elements.py", line 323, in _execute_on_connection
    return connection._execute_clauseelement(self, multiparams, params)
  File "/Users/classic/dev/sqlalchemy/lib/sqlalchemy/engine/base.py", line 1010, in _execute_clauseelement
    compiled_sql, distilled_params
  File "/Users/classic/dev/sqlalchemy/lib/sqlalchemy/engine/base.py", line 1146, in _execute_context
    context)
  File "/Users/classic/dev/sqlalchemy/lib/sqlalchemy/engine/base.py", line 1335, in _handle_dbapi_exception
    util.reraise(*exc_info)
  File "/Users/classic/dev/sqlalchemy/lib/sqlalchemy/engine/base.py", line 1116, in _execute_context
    context)
  File "/Users/classic/dev/sqlalchemy/lib/sqlalchemy/dialects/mysql/mysqldb.py", line 95, in do_executemany
    rowcount = cursor.executemany(statement, parameters)
  File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/pymysql/cursors.py", line 148, in executemany
    self._get_db().encoding)
  File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/pymysql/cursors.py", line 162, in _do_execute_many
    v = values % escape(next(args), conn)
UnicodeDecodeError: 'ascii' codec can't decode byte 0xc3 in position 64: ordinal not in range(128)
=================================================================== short test summary info ====================================================================
FAIL test/dialect/test_suite.py::UnicodeVarcharTest_mysql_pymysql::()::test_round_trip_executemany
======================================================== 139 tests deselected by '-kUnicodeVarcharTest' ========================================================
====================================================== 1 failed, 3 passed, 139 deselected in 0.27 seconds ======================================================
classics-MacBook-Pro:sqlalchemy classic$ 

```

the fix works all the way back for pymysql 0.4 which was five years ago so this is good for 0.9.