obviously I don't understand the new Flux language approach in influxdb2.

What I have:

A running influxdb1 instance where I write a json with different values for a measurement.

Now I have upgraded this influxdb to version 2. I can see in the UI the data and I can create queries where I fetch one of the values from a measurement.

But I have no clue how to fetch all of the values.

My query in influxdb1 was:

select * from "{my measurement}" ORDER BY time DESC LIMIT 500;

which have me the latest 500 measurement entries in an json array which I could use.

How can this be done with Flux now in influxdb2?

I tried something like this:

  'from(bucket: "{my bucket}")',
  '  |> range(start: -1d)',
  '  |> filter(fn: (r) => r._measurement == "{my measurement}")',
  '  |> mean()',
  '  |> yield(name: "_results")';

but I get the following error:

{"code":"invalid","message":"error in building plan while starting program: cannot submit unbounded read to \"{my bucket}\"; try bounding 'from' with a call to 'range'"}"

I am using a range parameter so I don't understand what is the problem with this query...