Hi,
I am trying to write this SQL coomand:
SELECT DISTINCT(col1, col2,col3) FROM mytable WHERE col1='something'
in sqlalchemy form:
columns=['col1','col2','col3']
*rows = session.query(*[func.count().over().label("count")]+map(lambda column:
MyClass.__dict__[columns],columns))*.filter(...).limit(n).offset(m).all()
this query works it returns the results together with the number of hits.
The problem is that when I apply the distinct() command
*rows = session.query(*[func.count().over().label("count")]+map(lambda column:
MyClass.__dict__[columns],columns))*.filter(...).limit(n).offset(m).*distict()*.all()
*func.count().over().label("count") does not show the correct number of hits
because func.count() relates to all column in table and to those selected -
that is col1, col2 and col3
My question is how to write the count function that will correctly count number
of distinct hits but only for the selected columns.*
I tried with:
*func.count().over(partition_by=MyClass.col1,MyClass.col2,MyClass.col3).label("count")*
*and it did not work
If I want to use:*
*func.count(distinct(MyClass.col1,MyClass.col2,MyClass.col3)).over().label("count")
only one column is allowed as the input argument for the count() function.
Is there any way to solve this?
Thanks*
Am Mittwoch, 16. Mai 2012 12:07:26 UTC+2 schrieb Eduardo:
>
> Hello,
> I have got a query of the following type:
>
> rows = session.query(*[func.count().over().label("count")]+map(lambda column:
> MyClass.__dict__[columns],columns)).filter(...).limit(n).offset(m).all()
>
> it returns the number of results together with values of selected columns.
> The problem is when I try to apply the distinct query I see that
> func.count().over().label("count") does not return correct results, that is,
> it returns the number of results for the query by which the distinct function
> is omitted.
> Is there any workaround for this problem?
> The query contains no joins.
> Thank you
> ED
>
>
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