Explanation about for
Νικόλαος Κούρας
nikos.kouras at gmail.com
Mon Jan 9 19:51:07 EST 2012
Στις 10 Ιανουαρίου 2012 1:42 π.μ., ο χρήστης Ian Kelly <
ian.g.kelly at gmail.com> έγραψε:
>
> > b) In the 2nd example we have for 'host, hits, agent, date in
> > dataset'. How does these 4 variables take their values out of dataset?
> > How dataset is being splitted?
>
> The second example works the same way as the first, except that
> instead of storing each row tuple in a single variable called row, it
> unpacks each tuple into four different variables named 'host', 'hits',
> 'agent', and 'date'. These represent the values of the selected
> columns from the query, for each selected row.
>
>
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!
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?
Excuse my english.
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