On Jan 8, 2012, at 3:16 PM, Yuen Ho Wong wrote:
> Except that LIMIT and OFFSET are present in my query, gnarly isn't
> it ? :P
>
> d = label("distance",
> some_complicated_geoalchemy_function_call(columns...))
>
> q = session.query(Product, Merchant.location, d)\
> .join(Merchant, Product.merchant_id == Merchant.id)\
> .filter(Product.numinstock > 0)\
> .options(subqueryload_all(Product.origin, Product.style,
> Product.foods, Product.flavors, Product.occasions, Product.moods,
> Product.varieties))
>
> q = q.order_by("distance").offset(0).limit(20).all()
LIMIT and OFFSET require an ORDER BY. Ordering is non-deterministic without
ORDER BY, so with LIMIT/OFFSET it means your results are non-deterministic as
well.
In fact you can't even use LIMIT/OFFSET on some databases without ORDER BY
present.
Without being able to run this it would appear you just need to order_by(d)
here. But the "distance" label should also be rendered into the subqueryload,
should just work that way too. Or try
order_by(func.some_complex_geoalchemy_function(...)).
You can also roll the subqueryload manually (a recipe is at:
http://www.sqlalchemy.org/trac/wiki/UsageRecipes/DisjointEagerLoading ).
If you have further problems please produce a .py file that actually runs -
what we need here is just "print q" to print the SQL generated by the query,
doesn't need to actually generate tables. You can omit all the extraneous
model objects and column too.
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