postgisqgis
I have a Postgis layer loaded in QGIS 2.8.6. There is empty POINT geometry field that I have to fill with geographic information.
How do I add features to this layer without adding new geometries? My intention is to complete the point field geometry with coordinates information.
For exemple, for the row 0 I have all the information but I have to complete it with the geometry information (In this case, UTM information).
If you're after a GUI solution, you can use the "Add Part" tool (QGIS >=2.2 only). First, make your layer editable. Then in an Attribute Table select a single row with a null geometry that you want to add a geometry to. Back in the map canvas, select the "Add Part" tool and draw your geometry. The null geometry will be replaced by your newly drawn shape.
If the database schema allows so, you can add geometry-less features in QGIS if the layer can be added as a non-geometric layer: SpatiaLite and PostGIS support this functionality if you enable the "show tables without geometry" option in their respective dialogs. Among the "tables without geometry" there will be also a "duplicate" (so to say) of the tables with a geometry field.
You can add both items for a single table and get two layers for one table.
The non-spatial layer will allow you to add new features (via the + button in the attributes table) where the geom field can be NULL (I repeat, if the database schema allows so):
Shapefiles don't allow this kind of work-flow as far as I know. It may not be orthodox, but it works and it can be useful in certain cases.
Best Answer
Figured this out! (also asked here)
A record in a spatial table (Shapefile, PostGIS, Spatialite) that has no geometry can have geometry added by adding a 'part' to the feature using the advanced digitizing toolbar. Here's the workflow:
Bring table containing the geometry-missing feature into QGIS
Select the layer from the layers panel and start an edit session on that layer
Right-click the toolbar area of QGIS (where there is no button) and open the advanced digitizing toolbar
Open the attribute table of the layer and select the feature that is missing geometry
On the advanced digitizing toolbar, click the add part tool
You can now add the geometry of the feature (point, line, or polygon) as you would add any new feature to a table
Save your edits, and stop editing.
The feature now has geometry!