The Update tool requires that the Input and Update datasets have matching schemas. The schema properties that are relevant and must match in this case are as follows:
- Fields must be the same (in both name and properties).
- Geometry must be of the same type (both POINT, or both LINE, and so forth)
- Both datasets must have Ms or neither must have m-values.
- Both datasets must have Zs or neither must have z-values.
Copy your inputs and modify the copied versions to have matching schemas and run Update on the copied versions of your inputs. Here is a procedure for easily creating feature classes with matching schemas. In this example there are two feature classes, named fc1 and fc2.
- Which feature class has the "desired" schema. Pick one (assume fc1).
- Run the Create Feature Class tool with these parameters set:
- The output location is the same location as fc1, if possible. If it is not, put it into a file geodatabase if fc1 is in a geodatabase or to a folder if fc1 is a shapefile.
- The name should be something like fc2_matching_schemaStep.
- For the Template Feature Class parameter, use fc1.
- For Coordinate system, import the spatial reference from fc1.
- Run the append tool with fc2 as the input and fc2_matching_schema as the target.
Evaluate fc2_matching_schema to make sure all the data (feature geometry and feature attributes) is there. If yes, run Update with fc1 and fc2_matching_schema.