You need to make sure that the key (identifier) you are using for each parentColumn is unique. For example, you have 3 dataTables: dataTable1, dataTable2, dataTable3. DataTable1 has a unique key column (ID1) and it will be the parentColumn for dataTable2. DataTable2 will have a unique key column (ID2) and the ID1 field can be multiple. Finally, dataTable3 will have a ID2 column with non-unique value.
Here is a diagram to illustrate this point:
dataTable1 —> ID1
dataTable2 —> ID1 ID2
Imported from legacy forums. Posted by CharlesB (had 7379 views)