On Apr 11, 2008, at 2:51 PM, Lukasz Szybalski wrote:
>
> Above statements should result in query like: 'select a,count(a) from
> x where b=5,c=6 group by a'
>
> In order to get ORM object I need to use query. (That is what I get
> from reading the sentence I quoted)
From the above, what ORM object would you like ? the one which has
"a" as one of its columns ? if so, the recipe I gave you is the
correct approach.
> What you emailed below is making a join if I read it correctly, and I
> don't think that is what I want.
>> sess.query(th).select_from(th_table.join(s,
>> th.RECORD_NO==s.c.RECORD_NO)).add_column(s.c.count).all()
>>
>
if you want to select a full row from the table, including its primary
key, and you'd like that row to correspond to a particular aggregate
query which needs to GROUP BY only part of the columns which does not
include the primary key column, you must use a join or subquery to
create the aggregate.
To illustrate, this is the query you think you want:
select *, count(a) from table group by a
Why "*" ? because you say that you want "ORM objects". The ORM
object represents the *full* row, including the primary key, of the
table.
but again, that query is invalid SQL. Most SQL-compliant databases
will raise an error. Another article explaining this:
http://weblogs.sqlteam.com/jeffs/jeffs/archive/2007/07/20/60261.aspx
.
Therefore, the join or subquery is necessary if you wish to GROUP BY
only particular columns.
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