How can I update Database Attributes With Projected XY Coordinate Values?
The Update Attributes command in GeoMedia can be used to update database attributes referenced by read write connections.
Although projected and geographic coordinates can be calculated using functional expressions for the update, expressions always use the coordinate system of the feature class (as it is stored in the warehouse).
The following step by step workflow demonstrates a method that allows you to calculate coordinates using any coordinate system (as defined by the GeoWorkspace).
1.Use Warehouse > Feature Class Definition to edit/review the feature class to be updated. Be sure that it has attribute columns such as Easting and Northing to hold the data. The data types for the attributes are important here. Typically, projected values should be stored as a DOUBLE and Geographic coordinates may be DOUBLE for Degrees or TEXT for DD:MMS
2.Use View > GeoWorkspace Coordinate System to set the coordinate system of the GeoWorkspace to the desired projection and datum. Once set you can optionally change your readouts to Projection east/northing and check the readout field to be sure the values are as expected.
3.Select Analysis > Analyze Geometry, pick the desired feature and desired coordinates to calculate.
IMPORTANT: Be sure to use the Units and Formats button here to set the desired precision for the coordinate type. Then run the query.
4.Once the query runs, and is displayed in map or data window, verify the results.
5.Select Edit > Update Attributes and be sure the pick the Geometry Info Query (NOT the original feature class). The update attributes command can trace the query back to the originating data records as long as the type of query has a 1:1 record relation with it's source table.
6.Click in the field to be updated.
Click the Expression button.
Build a function to update the attribute
To update X (easting) attributes the function might look like:
Where the Input.FirstProjectionCoordinate is selected from the list of attributes on the right side of the dialog.
To update Y (northing)
7.Add the expression(s) and use the Apply button to process the data.
Note: If you turn off the Undo option the Update will run much faster although you will NOT be able to undo any unexpected mistakes. Many users use Warehouse > Output to Feature Class to backup tables prior to using Update Attributes.