RE: ADX Studio Portal, WebSite Copy and other Tools to migrate data.
This is possible using the Configuration Migration Tool as you've referred to, but to do it smoothly requires several key conditions:
- The source environment must be an exact copy of the target environment
- The target environment must not change between the time the changes are made to the source environment and the export from it and import to the target environment is done
- When creating the data schema file, the fields to compare on update is set to the ID field of each entity, to ensure the records are matched by ID when determining if they already exist and which record to update, rather than the default behavior of matching on the primary field name which is problematic when multiple records have the same value in that field
- When creating the data schema file, exclude fields you don't care about and that are always different between multiple environments (e.g. createdon). You'll have to compare data exports between both environments to identify these fields and exclude them from the schema file prior to generating your final data set.
As you probably understand, this will import and update ALL records of the selected entities, not just the ones that have been modified, but with these conditions in place, the records that haven't been modified will essentially be a no-op during import because the records being imported are still the same, and the records that have been modified will get changed in the target environment.
If you want to be very specific on which records are imported, you could modify the XML in the data zip file and delete records which you don't want to be imported, but this could be very time consuming and lead to referential integrity problems if you're not careful.