I wanted to concatinate information of a column into a ; seperated column in a group by.
I want to count the number of project for each customer and see which managers and departments there are.
With a LISTAGG function this works
count(Project) as nr, LISTAGG(manager, ' ') WITHIN GROUP (order by manager) as managers
GROUP BY customer
ORDER BY customer
result will be
2 Mark;Piet BDO
1 Steven Microsoft