Thanks. That's what I thought.
I'm struggling a bit with multi-row queries.

'test' is phpunit test for QBE->SQL converter.

Currently generating:

SELECT DISTINCT
     `A/C#` AS `A/C#`,
     `MyRef` AS `MyRef`,
     `Dr` AS `Dr`,
     SUM(`Cr`) AS `Sum of Cr`
FROM
     `fuzzy`.`Debtor`
WHERE
     (`Cr` = '' OR `Cr` IS NULL)
     AND (`Dr` = '' OR `Dr` IS NULL)
GROUP BY
     `A/C#`,
     `MyRef`,
     `Dr`
ORDER BY
     BINARY `A/C#`,
     BINARY `MyRef`,
     `Dr`,
     `Sum of Cr`

Which I think is as you say.

On 25/2/21 8:02 pm, modridirkac wrote:
> If it has been working for 30 years, you don't need a test.  :)
> 
> Calculate sum for all rows, where Cr and Dr are the same?
> 
> Match:
> A   B   1       blank
> A   B   blank   1
> 
> Not a match:
> A   B   1       blank
> A   B   blank   2
> 
> 
> On Thu, 25 Feb 2021 02:32:15 +0100, Bernie van't Hof 
> <onrequest@somewhere> wrote:
> 
>> This one's been working for 30+ years but I can't write a unit test 
>> until I know exactly what it is meant to be doing:
>>
>> Query
>>
>> Debtor |   A/C#   |  MyRef   |    Dr    |      Cr      |
>>         | check _a | check _m | check _r | blank        |
>>         | _a       | _m       | blank    | _r, calc sum |
>>
>> Endquery
>>
>>
>> Any ideas?
>>
>>
> 
>