I have followed some examples for dissolving polygons in Spatialite and successfully created my simpler polygons:
SELECT "col1" sum("total") AS "total", st_union("GEOMETRY") AS "GEOMETRY" FROM "table" GROUP BY "col1";
I can preview these new shapes in Spatialite (Map Preview, Check Geometries), but they're not showing up as 'geometry' tables, with the little world icon, and I can't view them in QGIS.
I've seen examples that say I need to use something like this:
SELECT AddGeometryColumn('test_geom', 'the_geom', 4326, 'POINT', 'XY');
Can I convert the existing "geometry" column without adding a "geometry1" column?
Also, some of merged shapes are polygons and some are multipolygons due to minor errors in the original file coverage. I hope to edit the errors in the dissolve in QGIS, what new geometry type is best use for the table?