[TYPO3-dev] Extbase and group by

[Klaas Johan Kooistra]

Hi,

I need a group by query in Extbase and from what I've found so far this 
is impossible with the default Extbase functionality. What do I need it 
for? Consider the following models:
- Product: May exist in multiple Folders but is unique to each Folder
- FolderItem: Contains 1 Product
- Folder: May contain multiple FolderItems and is linked to a user

Now I need a listing of all FolderItems of a user. However, this will 
cause the same Product to be displayed multiple times if it exists in 
multiple Folders. The logical solution: Group by Product uid.

So I tried manipulating the query object, "manually" parsing the query 
in a custom extended TYPO3DbBackend method, adding a group by and then 
setting the query statement. This actually works for retrieving the data 
and you recieve a query result, which you can use for instance with the 
paginate view helper.

But then I added a count, which I need to display the number of items. 
And the number is wrong, because the count obviously does nothing with 
the modified statement. Unfortunately I can't figure out yet how to 
proceed from here and I'm hoping someone here may know a good solution.

Thanks in advance for any thoughts