By David Crowther
Question:
How can you List Unique Values for a layer within QGIS?
Answer:
The List Unique Values Tool allows you to interrogate and then list the unique values within one field of your GIS Layers.
In QGIS below we have a Polygon Layer representing some Planning Applications.
From the Processing menu choose > Toolbox > and open the Vector Analysis section.
Choose the List Unique Values menu option.
The List Unique Values tool will open.
We will use the following settings:
- In the Input Layer choose the Planning Applications Layer
- In the Target Field choose the Progress Field
If you Run the List Unique Values tool, it will identify all the Unique values in the chosen Target field and create a Temporary Table within the Layers panel.
If you Open the Attributes Table for the new Temporary Layer you can see a record for each Unique Value – in this example, each unique Planning Application ‘Progress’ value.
This is a very easy method to run a Select DISTINCT (Unique) statement without having to run your own complex SQL queries!