Pretty weird problem with SpatiaLite used within QGIS (2.13) with the DB Manager.
I have 2 layers (result of the same algorithm) and I use this function to merge them in a new table:
CREATE TABLE new_layer AS SELECT * FROM lay1 UNION ALL SELECT * FROM lay2;
The function works fine except for the fact that the new
Geometry column is recognized as
NUM Type and not as
MULTILINESTRING (the 2 starting layers have a correct
Geometry column type).
When I recover the geometry column, it is correctly recovered (so the layer is transformed into a geometric object) but still the
Geometry column is a
SELECT RecoverGeometryColumn('new_layer', 'Geometry', 3003, 'MULTILINESTRING', 'XY')
I think that this misunderstanding of SL can cause future incoherence with spatial operations.
Am I missing something?