Python DB API - commit() v. execute("commit transaction")?

[Jon Ribbens]

On 2017-05-31, Peter Otten <__peter__ at web.de> wrote:
> Jon Ribbens wrote:
>> You would do:
>> 
>>     cur.execute("SELECT ...")
>>     for row1 in cur.fetchall():
>>         cur.execute("SELECT ...")
>>         for row2 in cur.fetchall():
>>             ....
>> 
>> and as far as the database is concerned, the query is over and done
>> with as soon as you call fetchall(), so there is no possible overlap
>> between the different queries.
>
> It's easy to simulate an iterable cursor with
>
> iter(cursor.fetchone, None)
>
> and then two cursors instead of one start making sense again.

Indeed. I think this would not work, in general. For example, I think
with MySQLdb it would work if you use a standard Cursor class, as that
downloads the entire result set as soon as execute() is called, but it
would not work with the SSCursor class which downloads results as
needed. Again, this is because DB-API "cursors" are not SQL cursors.