X++ Odd count result - axapta

Question

I'm experiencing a really odd result when I do a count in X++, something I've not experienced before. I am performing what I thought was a really simply count query, but I can't seem to get the result I am after.
WMSOrderTrans orderTrans;
WMSOrderTrans orderTransChk;
;
select count(RecId) from orderTrans group by shipmentid where orderTrans.inventTransRefId == 'XXXXXX';
info(strFmt('Count is %1', orderTrans.RecId));
while select orderTransChk group by shipmentid where orderTransChk.inventTransRefId == 'XXXXXX' {
info(strFmt('Shipment is %1', orderTransChk.shipmentId));
}
The data set that I am selecting all have only 1 shipmentid, so the first select I am expecting a count of 1, instead I get 4 (which is how many lines for that transrefid exist). If I change the count from 'RecId' to 'ShipmentId', then instead of the count, I get actual shipmentId. I simply want it to return the count of the records, which is what I believe I've asked it to do.
I really can't see what I am missing.
In the while select, I get what I expect (the shipmentid), only 1 infolog message for the loop. This tells me that the group by with the where clause is working, but it doesn't explain why the first count select statement isn't behaving as I would expect.
For reference, this is AX2012 R1 system.

Answer 1

For anyone who might be interested in knowing my answer, it's tied up with Jeff's response. At the end of the day, I didn't look at data well enough, and the query returned the correct results. I initially thought there were a number of unique shipments, but I was wrong. My expected result was erroneous. There were 4 lines in the file, but the lines were unique for the item, not the shipment. They were all on the same shipment. So really, my own fault, it goes to show that one really needs to look at the data closely.
Thanks to all that responded, greatly appreciated.

Answer 2

I would try a database sync, then restarting the AOS. I don't see anything obviously wrong, so it points to bouncing everything.
Try getting the select statement via this method (from memory so check syntax) and then review the query against SQL directly. It uses generateOnly.
select generateOnly count(RecId) from orderTrans group by shipmentid where orderTrans.inventTransRefId == 'XXXXXX';
info(orderTrans.getSQLStatement());

Answer 3

If I understand what you try to achieve, you'd like to get something like this SQL query:
select count(distinct shipmentid) from orderTrans
where inventTransRefId = 'XXXXXX'
The 'distinct' keyword is not available in AX select command. The group by clause will allow you to iterate all distinct values but not to use an aggregate on top of it.
You may use a sql connection to push the exact sql command you want.
In AX, aggregate values are stores in the field used: Count(RecId), the count will go in the recid field otherwise the system may need to add new field on the buffer on the fly. I don't think you can aggregate on the group by clause as it's important to have its value.
You can try (I don't have an AX to test it) to use a query:
Query query = new Query();
QueryRun queryRun;
QueryBuildDataSource qbd;
qbd = query.addDataSource(tablenum(OrderTrans));
qbd.addRange(fieldNum(OrderTrans, InventTransId)).value("xxxx");
qbd.addSortField(fieldNum(OrderTrans, ShipmentId));
qbd.SortOrder(SortOrder::GroupBy);
queryRun = new QueryRun(query);
info(strfmt("Total Records in Query %1",SysQuery::countTotal(queryRun)));