cancel
Showing results for 
Search instead for 
Did you mean: 
Reply
New Member

Create Relationship on Compound Key

So, can someone tell me why I can't join tables on more than one key?  This seems like one of the most basic query functions yet it can't be done.  I see people saying 'create a calculated column', but how is that efficient?  Now the whole think becomes text and I likely need to pad the ID fields too to avoid incorrect keys.

6 REPLIES 6
Solution Sage
Solution Sage

@raeldor

 

In current Power BI, there exists a limitation for relationship that you can’t create relationship based on more than one column. 

 

To workaround this limitation, we can concatenate these related columns into one calculated column, then create relationship based on this concatenate column. Please refer:

 

1.PNG

 

2.PNG

 

Reference: Relationship in Power BI with Multiple Columns 

 

Thanks,
Xi Jin.

So, I know HOW to do it.  The question is really... why do I need to?

@raeldor

 

This is the limitation for relationship in current Power BI and it is by design. Smiley Sad

 

Thanks,
Xi Jin.

A little odd considering every relational database I've ever seen allows multi-field joins.  Seems a little unfair making users jump through hoops to do something so common. 😞

Regular Visitor

You can do it in M. If you choose in your transformation in Home/ "Merge Queries", you can highlight the 2 columns to match in both sides of the join.

 

@marianadinf what next? I merged the tables using 3 columns "Merge Queries" and "Merge Queries as New". With the first option it appears as a new column labled "Table", but I can't figure out how to add this data to the dashboard. When using "Merge Queries as New", a new table is created, but a) It doesn't have all columns, and b) the tables don't seem to be linked.

My expectation is that when I select a row in the "Parent" table visual, the "Child table" is filtered with just those rows.

Ex: 

Parent
A-1-x
A-1-y
A-1-z

Child
A-1-x-1

A-1-x-2
A-1-y-1

A-1-y-2
A-1-z-1

A-1-z-2

When I select a row in "Parent", "Child" only shows two rows.

Helpful resources

Announcements
November Update

Check it Out!

Click here to read more about the November 2020 Updates!

Community Conference

Power Platform Community Conference

Check out the on demand sessions that are available now!

secondImage

Power Platform October Community Highlights

Check out the top community contributors across all of the communities

secondImage

Create an end-to-end data and analytics solution

Learn how Power BI works with the latest Azure data and analytics innovations at the digital event with Microsoft CEO Satya Nadella.

Top Solution Authors
Top Kudoed Authors