Solved: What is wrong with simple query

I am very new to grafana, and I cannot understand why i don’t get any results in my chart.
In CLI is use this query : select * from “€/L” where (“entity_id” = ‘shell_leeuwarden’) and I get some results like this :
time domain entity_id friendly_name_str value
1580845263257926912 sensor shell_leeuwarden Shell Leeuwarden 1.6

This is my query in grafana that has no results:
SELECT mean(“value”) FROM “€/L” WHERE (“entity_id” = ‘shell_leeuwarden’) AND timeFilter GROUP BY time(__interval) fill(null)

I am familiar with sql but don’t understand the syntax of grafana:
for example : why does it say "from “€/L” while that is not a table ?
I could not find a simple tutorial about the syntax in queries. I found something on youtube but that did not help me any further.

Thanks in advance

I think it went wrong because I copied another panel to use it for these metrics.
Apparently Grafana sets some default values which made these values landing almost on the x-axis