Dear Gurus:
Please give your advice up front to help me avoid making a design error. I
am asking for help because:
1) I am not confident in my ability to understand Regular Expression
strings.
2) I do not know much about any dialect of SQL other than Microsoft T-SQL
(and sometime precious little of that.)
I am ready for the next step in development of adodbapi, which is to use
real ADO.NET (rather than COM ADO-db) when running on Iron Python.
My research indicates that, when using ADO.NET, one must choose to call
either an ExecuteReader() method, or an ExecuteNonQuery() method.
I am attempting to use a lightweight db-api implementation from FePy for my
pattern. It includes the following snippets of code:
<code snippet 1>
import re
P_IS_QUERY = re.compile('^[ \r\n]*SELECT ',re.IGNORECASE)
<code snippet 2>
class Cursor(object):
<code snippet 2A>
def _is_query(self, operation):
'''Identify whether an operation is a query or not'''
if P_IS_QUERY.match(operation):
return True
else:
return False
<code snippet 2B>
if self._is_query(operation):
self.reader = command.ExecuteReader()
self._set_description()
else:
command.ExecuteNonQuery()
self.description = None
</code>
It seems to me that this code could be confused by the substring 'SELECT'
being included as part of a longer string, or in a string literal. Am
reading it wrong?
It also seems to me that I should be able to detect a query by the fact that
the first token in the command will be either 'SELECT' or 'WITH, but would
that still be true for other dialects of SQL?'
I am thinking of using something like:
<code>
def is_query(operation):
return operation.split(' ')[0].upcase in ['SELECT','WITH']
</code>
Good idea, or Bad idea?
Any comments appreciated.
--
Vernon
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