What are some examples of Flux queries?

Can you show me some examples of Flux queries?

Sure! Flux is a powerful query language for querying time series data. Here are a few examples:

1. Basic Query: from(bucket: "my_bucket") |> range(start: -1h) retrieves data from the last hour.
2. Filtering: from(bucket: "my_bucket") |> range(start: -1d) |> filter(fn: (r) => r._measurement == "temperature") filters for temperature measurements.
3. Aggregation: from(bucket: "my_bucket") |> range(start: -1w) |> mean(column: "_value") calculates the mean value over the last week.

How can I filter data by a specific tag?

You can filter data by a specific tag using the filter function. For example: from(bucket: "my_bucket") |> range(start: -1d) |> filter(fn: (r) => r.device == "sensor1") will return data only from the device tagged as "sensor1".

What if I want to group the results?

To group results, you can use the group function. For instance: from(bucket: "my_bucket") |> range(start: -1w) |> group(columns: ["location"]) will group the data by the "location" tag.

Can I join two different data streams?

Yes, you can join two different data streams using the join function. For example: join(tables: {table1: table1, table2: table2}, on: ["_time"]) will join the two tables on the time column.