>Thank you Svein, that's what I tried but kept getting:
>SQL error code = -104.
>Invalid expression in the select list (not contained in either an aggregate function or the GROUP BY clause).
>
>and yet it now works. I thought it must have been because I was accessing code in the iif(...). I must have had a typo that
>I could not see for looking. Anyway, that now works perfectly, without the ',' after SH.

Sorry about not removing the comma after copying. I think your error might have been doing IIF(SUM... rather than SUM(IIF... Logically, that is using an aggregate to decide which single value to return (and hence, needs to be grouped by), whereas SUM(IIF takes a single value to determine which value should be used in the aggregation and doesn't need aggregation. When I try IIF(SUM..., I do get -104 as well.

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