On 03/25/12 17:59, Dennis Lee Bieber wrote:
On Sun, 25 Mar 2012 08:48:31 -0500, Tim Chase
Yeah, it has the same structure internally, but I'm somewhat
surprised that the DB connection object doesn't have an
__iter__() that does something like this automatically under the
covers.
I believe being able to use the connection object directly for
queries is considered a short-cut feature... If you use the longer form
con = db.connect()
cur = con.cursor()
the cursor object, in all that I've worked with, does function for
iteration
for rec in cur:
#do stuff
Interesting. Either this is something special for a particular
DB back-end, or has been added since I went hunting (back with
mxODBC and Python2.4). I wouldn't be surprised if the latter was
the case, as my code is nigh identical to yours.
conn = db.DriverConnect(connection_string)
cursor = conn.cursor()
cursor.execute(sql, params)
for row in cursor: # in the above 2.4 + mxODBC, this fails
process(row)
I'd be interested to know the underlying implementation's
efficiency, hopefully using .fetchmany() under the hood. My
understanding is that the .fetchmany() loop is the best way to do
it, as the .fetchone() gets chatty with the DB (but is more
efficient if you only need one row from a multi-result query),
and the .fetchall() can blow out memory on large datasets.
-tkc
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