Many-to-many relationships in Power BI and Excel - SQLBI
Jul 28, Many blogs, including some originating from our friends in the rainy Pacific The so-called Excel “data model” is actually a Power Pivot database and use the Power Pivot UI to create relationships between the tables. Feb 16, An article on Data Modeling for Power Pivot and Power BI as. Video: Relationships in Power View and Power Pivot to this problem is to split the data into multiple tables and define relationships between those tables.
In Find What, enter the key or column as a search term.
- Create relationships in Diagram View in Power Pivot
- Many-to-many relationships
- Many-to-many (data model)
Search terms must consist of field name. You cannot search on characteristics of a column or the type of data it contains. Click the Show hidden fields while finding metadata box. If a key was hidden to reduce clutter in the model, you might not see it in Diagram view. If a match is found, the column is highlighted in the table diagram. You now know which table contains a matching column that can be used in a table relationship. Change the active relationship Tables can have multiple relationships, but only one can be active.
The active relationship is used by default in DAX calculations and Pivot report navigation. Multiple relationships exist if the tables were imported that way, where multiple relationships were defined for that table in the original data source, or if you create additional relationships manually to support DAX calculations.
To change the active relationship, promote an inactive relationship.
The current active relationship becomes inactive automatically. Point to the relationship line between the tables. An inactive relationship appears as a dotted line. The relationship is inactive because an indirect relationship already exists between the two columns.
Right-click the line, and then click Mark as Active. You can only activate the relationship if no other relationship relates the two tables. If tables are already related, but you want to change how they are related, you must mark the current relationship as inactive, and then activate the new one.
Arrange tables in the Diagram view To see all the tables on the screen, click the Fit to Screen icon in the top-right corner of Diagram View.
many to many - Dealing with (multiple) many2many relationships in Excel Powerpivot - Stack Overflow
To organize a comfortable view, use the Drag to Zoom control, the Minimap, and drag the tables into the layout that you prefer. For example, for our sales transaction, we can have Who: Who placed the order? Whose credit card was used to pay for the transaction? Who was it shipped to? When was the order placed? When was it shipped? When did it arrive?
Pay It Forward
When was the customer invoiced? When did the customer finally pay? Matrix of Lookup and Data Tables As your model evolves and you pull in additional datasets, these should get plugged into Lookup tables in a matrix like fashion the rectangular array, not the movie ; well maybe a bit like the movie. Data sets should connect to a common set of Lookup tables click to enlarge any image in this article Even if the number of data tables in your model grow at a prolific rate, the lookup tables should remain a fairly stable set.
Your lookup tables typically represent the core entities in your business — like Customer, Product etc. On occasion as you bring in new datasets which typically represent business processesyou may need to add new lookup tables as well.
Create relationships in Diagram View in Power Pivot - Excel
But that exercise should be fairly infrequent. That is perfectly all right, in fact to be expected. For instance in the example above, Budget does not connect to Customer or Employee, since Budget is not set at Customer or Employee level at least for this example scenario. When using measures across two or more datasets in the same pivot or when using hybrid measures just be aware that only the common lookup tables would provide filtering on both datasets.
Create and manage relationships in Power BI Desktop
You may get invalid results if you use a lookup table which is only connected to one of the two data tables. Budget data table is not connected to Customer Lookup Table, thus you would get invalid results if you try to use them together Crazy Lookups and Snowflake: I have seen client models where everything is a lookup table and the diagram view looks like a mutant octopus.
Making every little thing into a lookup table is not good data modeling click to enlarge any image in this article Or where we have cascading Lookup tables also called Snowflake. Lookup Tables have Lookup Tables? That may not be ideal click to enlarge any image in this article None of these are considered good design for performance, scalability and usability reasons discussed next.
Your lookup table should represent something tangible and easily understood — e. Just be aware when you are not following the guidelines, understand why you are not doing so and account for possible implications.
Usability Star schema separate Data and Lookup tables would typically offer you the best performance and allow you to scale to millions of rows and multiple data sets. But another important implication is usability. Even for the simplest scenario where we have only one dataset — which of the field lists below would you like to use, day-to-day to build new reports and analysis? Star Schema would be much more user friendly once you start building reports More importantly, which field list would you want other users to be using who connect to your data model?
Think you are just creating a quick analysis model for yourself? Power Pivot is so powerful that you would often create models that last longer than you ever expect, be used by more people than you ever imagined.