2012/1/9 Νικόλαος Κούρας <nikos.kou...@gmail.com>: > if the MySQL query was: > > cursor.execute( '''SELECT host, hits, agent, date FROM visitors WHERE pin = > %s ORDER BY date DESC''', pin ) > > can you help me imagine how the mysql database cursor that holds the query > results would look like? I must somehow visualize it in order to understand > it!
You can think of it as a pointer, traversing over one row of the result set at a time. Hopefully this will come out legibly: ----------------------------------------------- | HOST | HITS | AGENT | DATE | ----------------------------------------------- ------------- | foo | 7 | IE6 | 1/1/11 | <---- | cursor | ----------------------------------------------- ------------- | bar | 42 | Firefox | 2/2/10 | ----------------------------------------------- | baz | 4 | Chrome | 3/3/09 | ------------------------------------------------ > Also what happend if the query was: > cursor.execute( '''SELECT host FROM visitors") ? > > the result would have to be something likelike? > > ----------------- > |somehost1| > ----------------- > |somehost2| > ----------------- > |somehost3| > ----------------- > ..................... > ..................... > |somehost n| > ----------------- > > So what values host, hits, agent, date would have in 'for host, hits, agent, > date in > dataset' ? Every row has one string how can that be split in 4? Why don't you try it and see what happens? But to spare you the suspense, you would get: ValueError: need more than 1 value to unpack Because you can't unpack a 1-length tuple into four variables. The code assumes that the query is selecting exactly 4 columns. -- http://mail.python.org/mailman/listinfo/python-list