This is typically done using a SQL trigger that listens for incoming geometries either from editing a map document or inserting geometries with SQL. When using a native DBMS spatial type such as SQL Server Geometry or Postgres' PostGIS type, constructor functions and spatial operator functions are provided that allow one to query different spatial properties.
For instance, in SQL Server we can use the
shape.Lat, shape.Long
functions for Geography types or
shape.X and shape.Y
for Geometry types on a spatial column called "shape".
Here is a simple SQL Server Geography example using shape.Lat and shape.Long. to update columns called "latitude" and "longitude" with their respective values. This sample is provided AS IS and must be properly tested before implementing in a production environment.
CREATE TRIGGER [gis].[Insert_xy_if_geometry_fc] ON [gis].[Landmark_fc]
AFTER INSERT
,UPDATE
AS
UPDATE pt
SET pt.latitude = i.Shape.Lat
,pt.longitude = i.Shape.Long
FROM Landmark_fc AS pt
INNER JOIN (
SELECT objectid
,Shape
FROM inserted
WHERE (Shape IS NOT NULL)
) AS i ON i.objectid = pt.objectid;
RETURN
GO
Lat (geography Data Type)
Long (geography Data Type)
