Relationships between three tables

[David_Billa]

Scenario -->
my customer is selling his products through three online services(A, B, C)

He wants to compare the sales, quantity,.. between them.

The issue here is there are no common fields among these three tables. So I am unable to create any relationships for them.
Is there a way to solve this issue?

Given data have no date column, products ids, product names none were matching.

3 are selling the same products though but the names given were different. 

[lbendlin]

Tell your customer to give you better data, including unique product identifiers that are consistent across platforms (or at least can be mapped) and transaction timestamps.

[Nicole_PBI]

On which level your customer wants to compare the data? Only grand total sales and grand total quantity?

Pretty easy: you don't need a relationship. Just create those two measures for each service and put them into a visual. And you are done. 

But actually I can't imagine that the source data just looks like this: 

Product_ID | Sales | Quantity

😉

If your customer wants to compare per product, asked them to provide a relationship table between the products of the different services.