On Jan 30, 2008 9:23 PM, Fred Cox <[EMAIL PROTECTED]> wrote:
> I've got a Postgresql DBI select:
>
> SELECT COUNT(*) AS voters, SUM(liked) AS liked, SUM(liked) / CAST( COUNT(*) AS
> real ) AS ratio FROM review_votes WHERE reviewid=?
>
> that works well, but I wasn't sure whether it would be practical to try to do
> this with RDBO.  I know the query builder works well, but that seems to be
> oriented to the WHERE clause.

The Manager is not going to help you with any query that does not
return a set of rows that correspond to an interconnected tree of
uniquely identified rows in one or more tables.  In particular, once
you add an aggregate function or group by clause, the resulting rows
no longer correspond to unique rows in a table and therefore cannot be
represented by Rose::DB::Object-derived objects.

The QueryBuilder may be of some use for building the actual SQL query,
but you will then need to run it using plain old DBI.  I suggest
encapsulating such queries in custom Manager methods.  That will hide
the DBI ugliness from calling code, and you can use (or not)
QueryBuilder internally depending on your needs.

-John

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