Why defaults to << To Both Tables >> in 1:1 relationships?

[ovonel]

I have a DimCustomer table (one key per row)… and I also use a Permit table that I created for RLS with also one customer key per row…

I have some doubts:

When I create the relationship (between Permit and DimCustomer, it defaults it as Many to One(*:1) , why is this? I thought the engine checked it had unique rows…

Anyway... I change it to One to One (1:1) and automatically the Filter Direction changes to << To Both Tables >> why is this?

I have this dax on the RLS:

=[PK_Customer] IN

SELECTCOLUMNS(

    FILTER(

        'Permit'

        ,' Permit'[UserName] = USERNAME()

        )

    ,"Cust"

    ,' Permit' [DW_SK_Customer]

)

So I only intend the filter to be from Permit to DimCustomer, will having it as << To Both Tables >> create me any issues?

[v-henryk-mstf · Accepted solution]

Hi @ovonel ,

Depends on the specific data model. When it is detected that a certain field in Permit has multiple rows corresponding to the unique field of DimCustomer. It is not possible to convert the relationship to one-to-one, as it will cause errors in the filter conditions. The many-to-one relationship does not affect the restrictions of RLS.

If the problem is still not resolved, please provide detailed error information and let me know immediately. Looking forward to your reply.

Best Regards,
Henry

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