On Friday, March 02, 2012 08:57:30 PM Ricardo Araoz wrote:

> El 02/03/12 20:24, Paul McNett escribió:

> > On 3/2/12 2:58 PM, Ricardo Araoz wrote:

> >> Let's say your large SQL statement has millions of rows and you want

> >> to

> >> group those rows in one data set and you want a subset of those rows

> >> in

> >> another data set. I'd rather recieve two datasets with 100 rows each

> >> (and processed in the dbms) than several million rows in one dataset

> >> and

> >> having to process it locally to obtain both final data set results.

> >

> > Python's dbapi provides for this with cursor.fetchmany(num_rows). Dabo

> > does not provide for this as it stands, because we always do

> > cursor.fetchall().

> Wouldn't that be fetching sets of rows of the SAME data set?

> What I need is to recieve two data sets from a single instruction.

> query = """

> select *

> into #TempTable

> from someBigTable

> left join someOtherTable

> on someConditions

> where someRestraints

>

> select someField, someOtherField, sum(someValue) as 'Total'

> from #TempTable

> group by someField, someOtherField

> order by someField, someOtherField

>

> select *

> from #TempTable

> left join #OtherTempTableFromSomeOtherPreviousQuery

> on SomeConditions

> where someOtherRestraints

> """

> If I sent this query to the dbms from VFP I would recieve two cursors,

> whose names would be by default (you may specify other) "cursor" and

> "cursor1".

> The "query" is defined by the user, so there is no way I may think of

> better or worse strategies, I want to get two different data sets so

> that I may later include them in a spread sheet or a csv file.

What is wrong with:

def getTwoDataSets(self, query1, query2):

dataSet1 = doSomethingWithQuery1

dataSet2 = doSomethingWithQuery2

return dataSet1,dataSet2

cursor1, cursor2 = getTwoDataSets("where pkid = 1", "where pkid =15")

Johnf

Johnf

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