Getting error in Table column contains a duplicate value, during incremental refresh

[Praveen_Rangu]

@lbendlin 

I am a pro PowerBI user and use RangeStart <= [partition date] < RangeEnd in this way. 
Even after doing in that way, I am getting the same error. Will it happen if that unique ID is present in archived data and got updated in a recent refresh 

Currently, I am using modified date to fetch data and detect changes. Instead, can I use created at date to fetch data and modified at date to detect changes. Will I escape from duplicate error.

Data source error: Column '<oii>class_id</oii>' in Table '<oii>dw v_fact_classes</oii>' contains a duplicate value '1333550' and this is not allowed for columns on the one side of a many-to-one relationship or for columns that are used as the primary key of a table.

[lbendlin]

Will it happen if that unique ID is present in archived data and got updated in a recent refresh 

Yes, it will. Remember this is incremental refresh, not differential refresh.  Incremental refresh only works with immutable data, If your data is mutable you need to manually refresh all affected partitions.

[Anonymous]

It is not allowed probably because it has a relationship to another table and this table is the one side of a one to many or one to one. Scroll to the right to see the rest of the error.

Or you mayve have to change the relationship to many to many or reverse the one to many if this is the fact and the other table is the dimension

[Praveen_Rangu]

I have updated the full reason.