I guess you can create a nested statement and do it all at once
def qSum = GQ {
from n in (
from s in sales
join w in warehouse on w.id == s.item
select w.name, w.price)
groupby n.name
select n.name, sum(n.price) as price
}
El dom, 6 oct 2024 a las 10:26, Per Nyfelt (<p...@alipsa.se>) escribió:
> I figured out a workaround i.e. to do it in two steps:
>
> def q = GQ {
> from s in sales
> join w in warehouse on w.id == s.item select w.name, w.price}assert
> [['Orange', 11.0], ['Orange', 11.0], ['Banana', 4.0]] == q.toList()
> def q2 = GQ {
> from w in q
> groupby w.name orderby w.name in desc select w.name, sum(w.price)
> }assert [['Orange', 22.0], ['Banana', 4.0]] == q2.toList()
>
> I submitted a feature request in Jira to support use of join, groupby and
> aggregate functions together.
>
> Regards,
> Per
>
> On 10/5/24 19:16, Per Nyfelt wrote:
>
> Hi, I am trying to learn Ginq and are having problems with joining an
> aggregation functions.
>
> The following example illustrates the issue:
>
> import java.time.LocalDate
>
> class Warehouse {
> int id
> String name
> Double price
> int stock
>
> Warehouse(int id, String name, Double price, int stock) {
> this.id = id
> this.name = name
> this.price = price
> this.stock = stock
> }
> }
>
> class Sales {
> LocalDate date
> int item
>
> Sales(LocalDate date, int item) {
> this.date = date
> this.item = item
> }
> }
>
>
> List<Warehouse> warehouse = [
> new Warehouse(1, 'Orange', 11, 2),
> new Warehouse(2, 'Apple', 6, 3),
> new Warehouse(3, 'Banana', 4, 1),
> new Warehouse(4, 'Mango', 29, 10)
> ]
> List<Sales> sales = [
> new Sales(LocalDate.of(2024, 5, 1), 1),
> new Sales(LocalDate.of(2024, 5, 2), 1),
> new Sales(LocalDate.of(2024, 5, 3), 3)
> ]
> def q = GQ {
> from s in sales
> join w in warehouse on w.id == s.item
> select w.name, w.price
> }
> // so far so good, the following works:
> assert [['Orange', 11.0], ['Orange', 11.0], ['Banana', 4.0]] ==
> q.toList()
>
> // now try to summarize by name
> def qSum = GQ {
> from s in sales
> join w in warehouse on w.id == s.item
> groupby w.name
> select w.name, sum(w.price)
> }
> // Fails with Exception evaluating property 'price' for
> groovy.lang.Tuple2,
> // Reason: groovy.lang.MissingPropertyException: No such property: price
> for class: Sales
> assert [['Orange', 22.0], ['Banana', 4.0]] == qSum.toList()
>
> So for some reason ginq thinks it will find the price property in the
> Sales class instead of in the Warehouse class so w.price here is not
> understood. What is the right way to write it?
>
> Regards,
>
> Per
>
>
