Thank you for your participation in the discussion.
For me, the problem is not that I don’t feel comfortable learning the advanced queries, but that important information is missing and prevents this.
On the one hand, simple queries don’t work as they should in theory and are still very limited:
On the other hand, important information is missing to write the advanced queries myself (that’s why I asked for more documention).
Fortunately, there are very helpful people here who also help with concrete requests , but some request stay unanswered.
In the meantime, I’m also collecting all kinds of practical queries and trying to learn from them.