I have a multi polygon with spatial field layer with and 3000 records and I want to use dissolve all in 1 record.
On DISSOLVE algorithm in QGIS you have a choose to dissolve all features from layer that I want with PostGIS.
After the query I want to have one record and this record have all.
I test this query :
SELECT (ST_Dump(ST_union(geom))).geom::geometry(POLYGON,2100) FROM public.parcel1
but don't work; don't create me one record with all features.
What have I done wrong?