How do I SUM column in join?

[kwiliodev]

I am trying to get a sum of bills for each category. I see the .sum() only seems to work on the selected table but not the joined table.
How can I return a column similar to the 'amountOfBills' count but a sum of the 'amount' column in the related bills?
Thanks.

Stream<List<CategoryWithTypes>> streamCategoryWithTypes() {
    final amountOfBills = bills.id.count();

    // add sum of bills [ ISSUE HERE]
     final sumOfBills = bills.amount.sum();

    final query = select(categories).join([
      leftOuterJoin(types, types.id.equalsExp(categories.typeId)),
      leftOuterJoin(bills, bills.categoryId.equalsExp(categories.id) & bills.deletedAt.isNull()),
    ]);
    // order by category name ascending
    query.orderBy([OrderingTerm.asc(categories.name)]);
    query.addColumns([bills.id.count()]);
    query.groupBy([categories.id]);

    // see next section on how to parse the result
    return query.watch().map((rows) {
      
      return rows.map((row) {
        return CategoryWithTypes(
          row.readTable(categories),
          row.readTable(types),
          row.read(amountOfBills),
          row.read(sumOfBills)
        );
      }).toList();
    });
}

[simolus3]

Were you able to resolve the problem? Out of interest, what was the problem with that snippet? It looks correct to me.

[kwiliodev]

Yes, I was able to resolve. The issue was that my column was a TextColumn. I changed it to RealColumn.
Works great now, thank you!