redirecting py-dev thread here On 05/21/2015 07:06 PM, Greg wrote:
On 22/05/2015 1:33 p.m., Ethan Furman wrote:
Going back to the OP:
select(c for c in Customer if sum(c.orders.price) > 1000)
which compile into and run SQL like this:
SELECT "c"."id" FROM "Customer" "c" LEFT JOIN "Order" "order-1" ON "c"."id" = "order-1"."customer" GROUP BY "c"."id" HAVING coalesce(SUM("order-1"."total_price"), 0) > 1000
That last code is /not/ Python. ;)
More importantly, it's not Python *semantics*. You can't view it as simply a translation of the Python expression into a different language.
Ah, I think I see -- that 'select' isn't really doing anything is it? The 'if' clause is acting as the 'select' in the gen-exp. But then `sum(c.orders.price)` isn't really Python semantics either, is it... although it could be if it was souped up -- `c.orders` would have to return a customer-based object that was smart enough to return a list of whatever attribute was asked for. That'd be cool. -- ~Ethan~