A bit like LOOKUPs in Excel, how to use it, when to use it #PowerBI #PowerBIRelated #dataanalytics https://www.selectdistinct.co.uk/2023/03/15/power-bi-related-function/

1. Power BI Tips
and Timesavers
How to use
RELATED in Power
BI
LOOKUP
Table A Table B

2. What is the Power BI RELATED function
The RELATED function in Power BI is a powerful tool that allows users to
quickly and easily access related data from a related table
It is similar in many ways to using lookups in Excel (VLOOKUP)
In this example we will use the Related function to return a standard cost per
mile using a type of vehicle as a lookup reference

3. How to use it
You can download the Excel file from our site to follow along

4. Load the Data and set the
relationships
Vehicle in the Miles tables joins to the
Vehicle ID in the Vehicles Table
Type in the Vehicles table joins to the
Vehicle Type in the Costs Table
Vehicle Type ID in the Vehicle Types table
joins to the Vehicle Type in the Costs table

5. Add a summary table to the page
Drag a new table visual object to the canvas and bring these fields in
Vehicle from the Miles table, Vehicle Type Name from the Vehicle Types
table, Cost per Mile from the Costs table and Sum of the Distance [mi]
from the Miles table

6. Now add the calculated
column
On the data pane, select the Miles table and click
the New Column icon
Then paste in this DAX code
Mileage Cost
= related(Costs[Cost per Mile ])*Miles[Distance
[mi]]]
press enter and the new column is created

7. The RELATED Function
Mileage Cost
= related(Costs[Cost per Mile ])*Miles[Distance
[mi]]]
This highlighted section is the related function, it
requires two parts
The Table Name
= related(Costs[Cost per Mile ])
And the Field Name
= related(Costs[Cost per Mile ])

8. Errors to avoid
The Related function only works when a single value can be returned
It cannot work if there is no clear relationship to return a single value, if a
relationship returns many possible results it cannot be used
The solution there is to use RELATEDTABLE and perform a aggregation, this topic
will be covered in a future post so it can be fully explained

9. The Related function is easy to learn, especially if you have some experience
of using LOOKUPS in Excel, and can help to simplify your data modelling
There is not much to go wrong if you focus on getting the correct
relationships between your tables
We hope you find this useful

10. For more Tips, Tricks and
Timesavers, visit our website
Business Analytics Blog – Select Distinct
Credit: simon.harrison@selectdistinct.co.uk