I want to write a command that creates a virtual layer for me as a buffer from lines with different distance parameters, for example 5 and 10 km. I want this to be possible in one layer, the geometry generator does not meet my expectations because it needs geometry.
SELECT new_field,
st_union(st_buffer(geometry,5)),(st_buffer(geometry,10)) as geometry
from bufor_
To have distinct polygons for each buffer size, create a list of distances and join it to the original table.
Go to the menu Layer > Add Layer > Add/Edit Virtual Layer... and enter the following query. Adjust the layer and field names.
WITH config(dist) as (values (2000),(5000),(10000))
SELECT st_buffer(geometry,dist) as geometry,
dist, pt.id, pt.other_fields
FROM pt, config;
