Join columns from different tables in the data model

Nima Mohandesan 

Let me illustrate on the simple model. Let say we have two queries

First one we use to add some data to data model, second one will be used to generate linkback table. They are

ConnectionOnly:
let
    Source = #table({"A","B"},{{1,2},{3,4}})
in
    Source

DataModelandTable:
let
    Source = #table({"X","Y"},{{11,22},{33,44}})
in
    Source

We load second one as

Now in data model we have second query plus all the rest from our data model (in a circle)

In the sheet we have laded by left query table 

Right click on it, Table->Edit DAX->command type: DAX-> add your DAX evaluate expression.

Here is the simplest DAX, just to return another table from data model

Press Ok and instead of initial table we have what DAX returns

Above is one of variants to illustrate the idea. Minor modification - you may not load second query to the Excel sheet, let assume it's also part of the model. With this you may select any query from Existing Connections

load it as the table from here and modify by DAX as before. DAX expression could be as complex as needed.