Note: This article pertains to retired ArcGIS versions 9.x only. Later versions of ArcGIS may contain different functionality, as well as different names and locations for menus, commands and geoprocessing tools. This issue is addressed in ArcGIS 9.0 Service Pack 2 (SP2).
If two tables are joined, Table B is joined to an origin Table A, there are issues when attempting to use the Calculate Field tool. In ArcCatalog, the geoprocessing scripting environment and ModelBuilder, it is not possible to calculate any field after two tables have been joined. In ArcMap, users are able to calculate fields in the origin table (Table A) but not the join table (Table B).
This is a known issue. This functionality is not supported in the 9.0 release, however, it is supported in the Service Pack 2 and subsequent ArcGIS releases.
If the Service Pack 2 is unavailable, use the workaround below. If the information in a field from a separate table is needed to perform a calculation, the operation must be performed in ArcMap. Only fields in the origin table or feature class can be calculated.
Note: In ArcMap 10.x, the Field Calculator can only calculate values for fields in the origin table after a join. Refer to ArcMap: Reasons the Field Calculator might be disabled for more information.