Confirmed: Cross Application relationships require the primary key to be manually updated via VLOOKUP/bulk import.
Also we cannot really copy the app as a backup since the copy will reference the same parent app. Copying the parent app does not re-produce the relationship, must copy the child. So to get a proper copy would need to copy the child app and parent app, then rebuild the relationship
from scratch in the child app copy with the parent app copy. Basically what happens in primary key change is the lookups no longer work until the records are updated with the proper key IDs. So not really losing information, just temporarily doesn�t display. A primary key change does not delete the relationship, lookup fields and their settings, etc.
The general MOP is as follows:
1. Identify relationships that need key update - any arrow pointing *away* from the table you are changing the key in will need a manual update via bulk import/VLOOKUP
2.
Create lookup reports for each table with the table�s primary key (Record ID#) and the related field.
May have to enable the field�s �The field may be used in reports� option to create lookup reports. Turn it on quickly, as soon as save report, turn it off. This just changes the fields availability in new reports, not existing ones.
3. Create bulk import spreadsheet with VLOOKUP translation for each target table.
4. Make sure no users are making changes to system
5. Move primary key �
WARNING � This orphans the relationship but the data will re-appear after we re-import the correct primary key
6. Import VLOOKUP bulk imports to target tables
7. Test a few records to confirm the change
8. Update any bulk import templates with the new primary key data. Send any users doing bulk imports the new primary key to old primary key translation table.
9. (if applicable) Delete old primary key after a few weeks of no issues.
