Problem: Route features are being merged by the APPEND command


When using the APPEND command to combine coverages containing route features, the output coverage contains fewer route features than the total number of route features in the input coverages.


The APPEND command will merge route features from different coverages into a single feature if they have the same route User-ID.

At ArcInfo version 8.1, the APPEND command has been changed so that route features will not be merged when the FEATURES or ALL option is used.

Solution or Workaround

  1. Make sure the route User-IDs are unique between all route subclasses for all input coverages. You can use TABLES to select the route attribute table of one of the coverages to be appended, and calculate the route User-IDs to a unique value:

    Arc: tables
    Tables: select roads1.ratbus
    Tables: calculate bus-id = bus#

    Please note the highest User-ID in this coverage before moving to the next step.

  2. Select the route attribute table of another coverage to be used as input for APPEND. Calculate the User-IDs of this route system to be unique and use the highest User-ID from the previous step as an offset to keep the IDs unique between coverages. For example, if the highest User-ID in the previous coverage was 100, start the User-IDs for this coverage at 100:

    Tables: select roads2.ratbus
    Tables: calculate bus-id = bus# + 100

  3. Repeat the User-ID calculation for all route features in the coverages to be used with the APPEND command. Always check the highest User-ID from the previous coverage and use it as the starting value for calculating unique User-IDs in the current coverage.

  4. Run APPEND again once you have calculated all the route User-IDs for all of the input coverages to be unique.

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