Intended way to get InfluxDB2 results into POJOs in Java?

Client SDKs
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1

I’m able to insert to InfluxDB2 (on-prem) just fine with the influx-client-java, however I’m unsure how to properly “deal with” query results, which I get as a List<FluxTable>. Is there any simple way to get such a result back into POJOs, or use some other query function?

I’m using client.getQueryApi().query("my flux query", "myorganization").

2

Hi @Bob_Doe,

thanks for using our client.

Check it out this example - influxdb-client-java/SynchronousQueryPojo.java at master · influxdata/influxdb-client-java · GitHub

Regards

1 Like
3

Thanks for your reply. I was able to review it, but as I’m fairly new to Influx apparently I don’t quite get it.

Say I have the following: A object that has two fields, say “val_a” and “val_b”. How am I able to convert a Flux query result back into a POJO while getting the following into variables:

  • The measurement name
    • Say I ask for “measurement is X or Y or Z”, then I’d like my POJO to know if it is X or Y or Z.
  • The value for BOTH “val_a” and “val_b” in a single POJO
    • Here I seem to get one but not the other. Is this because the POJO converter only concerns itself with a single FluxRecord…? I might be getting something wrong here.

So say that I insert:

my_measurement_1
  val_a = 1.23456
  val_b = 555

I’d like to query it out asking for for multiple measurements

  • e.g. a filter for r["_measurement"] == "my_measurement_1" or r["_measurement"] == "my_measurement_2" ... an
  • And a filter for r["_field"] == "val_a" or r["_field"] == "val_b"

And then be able to bring this back into X separate POJOs which all look (ideally, or as close as possible) like this (pseudocode):

[
Result {
  String name = "my_measurement_1";
  Double valA = 1.23456;
  Integer valB = 555;
}, 
Result {
  String name = "my_measurement_2";
  Double valA = 2.46802;
  Integer valB = 999;
},
...
]

Feel free to modify if I’m modeling or querying poorly, or if I’m missing something else entirely.

My current, rather unsuccessful attempt is something like:

@Measurement(name = "measurement") // ??? Dynamic? Why specific name?
public class Result {
  @Column(name = "val_a")
  Double valA;

  @Column(name = "val_b")
  Integer valB;

  @Column(timestamp = true)
  Instant time;
}
4

After better understanding Influx and the way responses work I realize the fault was that I needed to pivot the column to get them in the same row.

Doing this pivot I could get them by name and also get what I call the “measurement name” with column named _measurement. E.g., after pivot:

public class Result {
  @Column(name = "_measurement")
  String measurement;

  @Column(name = "val_a")
  Double valA;

  @Column(name = "val_b")
  Integer valB;

  @Column(timestamp = true)
  Instant time;
}

Pivot could be like:

  |> pivot(rowKey: ["_time"], columnKey: ["_field"], valueColumn: "_value")
5

@Bob_Doe sorry for the late.

You are right the pivot and the @Column(name = "_measurement") are valid solutions.