MySQL Error

[MRAB]

Benjamin Kaplan wrote:
> On Fri, Jan 1, 2010 at 1:32 PM, Victor Subervi <victorsubervi at gmail.com> wrote:
>> On Fri, Jan 1, 2010 at 12:10 PM, MRAB <python at mrabarnett.plus.com> wrote:
>>> Victor Subervi wrote:
>>>> Hi;
>>>> I'm trying to avoid the mortal sin of blank excepts. I intentionally
>>>> threw this error:
>>>>
>>>> Traceback (most recent call last):
>>>>  File "/var/www/html/angrynates.com/cart/createAssociations2.py
>>>> <http://angrynates.com/cart/createAssociations2.py>", line 137, in ?
>>>>    createAssociations2()
>>>>  File "/var/www/html/angrynates.com/cart/createAssociations2.py
>>>> <http://angrynates.com/cart/createAssociations2.py>", line 108, in
>>>> createAssociations2
>>>>    cursor.execute(sql)
>>>>  File "/usr/lib64/python2.4/site-packages/MySQLdb/cursors.py", line 163,
>>>> in execute
>>>>    self.errorhandler(self, exc, value)
>>>>  File "/usr/lib64/python2.4/site-packages/MySQLdb/connections.py", line
>>>> 35, in defaulterrorhandler
>>>>    raise errorclass, errorvalue
>>>> ProgrammingError: (1146, "Table 'test.productsAssociations' doesn't
>>>> exist")
>>>>
>>>> However, "ProgrammingError" is not an error. How do I discover the real
>>>> error, so I can write the appropriate except statement?
>>>>
>>> What makes you think it isn't?
>> Because I've tried
>> except ProgrammingError:
>>   pass
>> before and *that* threw an error. So I didnt' try again.
>> beno
> 
> Just because it's not in the current namespace doesn't mean it's not
> an error. From PEP 249 (the db api v2) :
> 
>   ProgrammingError
> 
>             Exception raised for programming errors, e.g. table not
>             found or already exists, syntax error in the SQL
>             statement, wrong number of parameters specified, etc.  It
>             must be a subclass of DatabaseError.
> 
You shouldn't just that it threw an error and give up, you should look
at what the error was, in this case a NameError, which means that it
doesn't know that name. Why? Because it's defined in the MySQL module
that you imported, but you didn't import the name ProgrammingError.