Hi,
I am trying to create a data expression to pull out a dataset that just contains the most recent survey results for several survey stations at various locations. My main feature layer contains fields for location ("Location", string), survey station id ("StationID" field, string), survey date ("SurveyDate" field, date) and survey result ("CheckResults", string (either 'Positive' or 'Negative')).
This is similar to a previous query raised on this forum "Data Expressions using GroupBy and Filter" but the solution to this doesn't work in this case unfortunately as all survey stations aren't necessary surveyed on the same day each time. So the most recent record for station A1 may have a different date to the most recent record for station A2 for example.
An example of my data is shown below:
Location | StationID | SurveyDate | CheckResults |
A | A1 | 01/10/2019 | Negative |
A | A2 | 12/09/2021 | Positive |
A | A3 | 05/06/2021 | Negative |
B | B1 | 05/06/2021 | Positive |
B | B2 | 28/06/2020 | Negative |
A | A1 | 22/10/2016 | Negative |
A | A2 | 15/09/2020 | Negative |
A | A3 | 03/05/2019 | Positive |
B | B1 | 04/05/2019 | Negative |
B | B1 | 06/04/2018 | Positive |
What I would like to return:
Location | StationID | SurveyDate | CheckResults |
A | A1 | 01/10/2019 | Negative |
A | A2 | 12/09/2021 | Positive |
A | A3 | 05/06/2021 | Negative |
B | B1 | 05/06/2021 | Positive |
B | B2 | 28/06/2020 | Negative |
Any help on how to do this would be really appreciated.
Many thanks,
