Incorrect behavior of "parameter_id" in "v2/latest" endpoint ?

[kalisio-nicolas]

Issue Description:

Hello, I am encountering unexpected behavior when using the parameter_id parameter in the v2/latest endpoint. Specifically, I am attempting to filter results for a specific parameter, such as Ozone mass concentration by providing its corresponding identifier, such as 3. However, the endpoint is returning measurements for other parameters, such as pm10 and co which should not be included.

Here is the URL I am using:

https://api.openaq.org/v2/latest?country_id=2&parameter_id=3

Expected Behavior:

• When I use the parameter_id parameter, I expect the endpoint to filter and return only measurements for the specified parameter, in this case, Ozone mass concentration (parameter_id=3).

Actual Behavior:

• The endpoint is returning measurements for multiple parameters, including Ozone mass concentration, pm10, co and possibly others. Additionally, the presence of the parameter_id parameter appears to affect the number of results returned, meaning that the parameter is being treated as a filter, but not as expected.

With the measurements endpoint, filtering by type works as expected, and in addition, the old parameters country and parameter still function. Especially, with the old parameter, we could include multiple parameters in a single request, such as pm10 and pm25 in one query. However, with the latest endpoint, we can only use parameter_id, which can only accept one variable per request, and it also does not behave as expected. https://api.openaq.org/v2/measurements?location_id=65998&limit=1000&date_from=2023-09-18T00:00:00Z&parameter=pm25&parameter=pm10

Am I missing something ? Or is this a bug ? thanks for your help.

[russbiggs]

@majesticio can you take a look at this?

[majesticio]

@kalisio-nicolas Hello, this is actually expected behavior. When you use parameter_id=3 it will return location objects that contain that parameter, it doesn't reshape the data for you. Likewise, when you call a location by its ID the API will return that location object, the parameter= query params won't reshape the data, but date_from and date_to will get the desired range of measurement objects from that location. Hope this helps!

[russbiggs]

closing since this is expected behavior in v2