[Sqlalchemy-tickets] [sqlalchemy] #2871: UnicodeDecodeError is thrown instead of StatementError if the statement with non-ASCII symbols lacks parameter bind value

[sqlalchemy <mi...@zz...>]

#2871: UnicodeDecodeError is thrown instead of StatementError if the statement
with non-ASCII symbols lacks parameter bind value
----------------------+---------------------------------------
 Reporter:  pupssman  |           Owner:  zzzeek
     Type:  defect    |          Status:  new
 Priority:  medium    |       Milestone:  0.8.xx
Component:  engine    |        Severity:  minor - half an hour
 Keywords:            |  Progress State:  awaiting triage
----------------------+---------------------------------------
 Environment: Ubuntu 12.04, python 2.7.3, SA 0.8.2,
 sys.getdefaultencoding() => 'ascii'

 What we do:
 run `Session.execute` against SQL statement with a non-ASCII symbols that
 declares a bind parameter but has it not fullfilled.

 What do we expect:
 A `StatementError` with text `A value is required for bind parameter 'x'`
 is thrown

 What do we observe:
 A `UnicodeDecodeError` is thrown instead.

 Sample script:

 {{{
 #!python
 # encoding: utf-8
 from sqlalchemy.engine import create_engine
 from sqlalchemy.orm.session import sessionmaker


 def test_foo():
     engine = create_engine('sqlite://')
     engine.execute('create table test (value varchar(100))')
     session = sessionmaker(bind=engine)()
     session.execute(u"""
     --- КИРИЛЛИЦА
     insert into test values (:x)
     """)


 if __name__ == '__main__':
     test_foo()
 }}}

 In the absence of `--- КИРИЛЛИЦА` line this throws a proper
 `StatementError`:
 {{{
 Traceback (most recent call last):
   File "test_a.py", line 15, in <module>
     test_foo()
   File "test_a.py", line 12, in test_foo
     """)
   File "/usr/lib/python2.7/dist-packages/sqlalchemy/orm/session.py", line
 934, in execute
     clause, params or {})
   File "/usr/lib/python2.7/dist-packages/sqlalchemy/engine/base.py", line
 662, in execute
     params)
   File "/usr/lib/python2.7/dist-packages/sqlalchemy/engine/base.py", line
 761, in _execute_clauseelement
     compiled_sql, distilled_params
   File "/usr/lib/python2.7/dist-packages/sqlalchemy/engine/base.py", line
 828, in _execute_context
     None, None)
   File "/usr/lib/python2.7/dist-packages/sqlalchemy/engine/base.py", line
 1024, in _handle_dbapi_exception
     exc_info
   File "/usr/lib/python2.7/dist-packages/sqlalchemy/util/compat.py", line
 195, in raise_from_cause
     reraise(type(exception), exception, tb=exc_tb)
   File "/usr/lib/python2.7/dist-packages/sqlalchemy/engine/base.py", line
 824, in _execute_context
     context = constructor(dialect, self, conn, *args)
   File "/usr/lib/python2.7/dist-packages/sqlalchemy/engine/default.py",
 line 438, in _init_compiled
     grp, m in enumerate(parameters)]
   File "/usr/lib/python2.7/dist-packages/sqlalchemy/sql/compiler.py", line
 367, in construct_params
     % bindparam.key)
 sqlalchemy.exc.StatementError: A value is required for bind parameter u'x'
 (original cause: InvalidRequestError: A value is required for bind
 parameter u'x') '\n    insert into test values (?)\n    ' [{}]
 }}}


 But the actual error is:
 {{{
 Traceback (most recent call last):
   File "test_a.py", line 16, in <module>
     test_foo()
   File "test_a.py", line 13, in test_foo
     """)
   File "/usr/lib/python2.7/dist-packages/sqlalchemy/orm/session.py", line
 934, in execute
     clause, params or {})
   File "/usr/lib/python2.7/dist-packages/sqlalchemy/engine/base.py", line
 662, in execute
     params)
   File "/usr/lib/python2.7/dist-packages/sqlalchemy/engine/base.py", line
 761, in _execute_clauseelement
     compiled_sql, distilled_params
   File "/usr/lib/python2.7/dist-packages/sqlalchemy/engine/base.py", line
 827, in _execute_context
     str(statement), parameters,
 UnicodeEncodeError: 'ascii' codec can't encode characters in position
 9-17: ordinal not in range(128)
 }}}

 This is causes here:
 https://github.com/zzzeek/sqlalchemy/blob/master/lib/sqlalchemy/engine/base.py#L827

 Strangely, but it is the only place where `str(statement)` is called in
 preparation for `self._handle_dbapi_exception` call. Looks like the `str`
 part is superfluous.

--
Ticket URL: <http://www.sqlalchemy.org/trac/ticket/2871>
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