On 21/10/14 19:57, Al Bull wrote:
have multiple records per ord_dbasub. Is there a way I can structure the
select statement to retrieve only the most current record (based on
ord_date)?
Yes, the cursor can be told to only retrieve N records, in your case 1.
SELECT ord_dbasub, ord_pub,ord_date,ord_service,
...
FROM ord
WHERE ord_pub='QWKFIL'
ORDER BY ord_dbasub, ord_date
LIMIT 1
If the sort order is wrong you can specify ASC or DESC to reverse
it as needed.
ord_rows = cursor.execute("select ord_dbasub, ord_pub,
ord_date,ord_service,"
"ord_agency, ord_woa, ord_status,"
"ord_channel, ord_source, ord_giftcomp,"
"ord_cnreason "
"from ord "
"Where ord_pub='QWKFIL'"
"order by ord_dbasub, ord_date").fetchall()
Rather than all those quotes you can use triple quotes:
ord_rows = cursor.execute('''select ord_dbasub, ord_pub,
ord_date,ord_service,
ord_agency, ord_woa, ord_status,
etc...
order by ord_dbasub, ord_date
limit 1''').fetchall()
for row in ord_rows:
print (row.ord_dbasub, row.ord_date, row.ord_pub)
# Add code here to find the most recent order per DBASUB and delete other
orders
If it's in order you could just access the first row using an index.
print (ord_rows[0])
I have to admit that the concept of tuples & dictionaries has me a little
bit confused. I'm used to working with arrays and arrays of structures.
tuples are just read-only lists, which, in turn, are arrays that can
hold any data type.
tuples are also like records without named fields. You can use a named
tuple from the collections module which is even more like a record.
--
Alan G
Author of the Learn to Program web site
http://www.alan-g.me.uk/
http://www.flickr.com/photos/alangauldphotos
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