Concatenate Tabular Analysis Service

Question

Suppose I have a data model with SSAS-Tabular Analysis Service. In this data-model I have multiple tables but for ease suppose I have "Table1", "Table2" and "Table3". Each of these tables have a column named "Source.Name" which indeed indicates each of the files read by that table. Q: I want to write a function "EVALUATE" to be used with DAX Studio or with Pyadomd to take all the values of these columns and concatenate in order to have an array/list of "Source.Name"s. How could this be done?

Answer 1

EVALUATE

UNION(
    SELECTCOLUMNS(Table1, "a", Table1[Source.Name]),
    SELECTCOLUMNS(Table2, "a", Table2[Source.Name]),
    SELECTCOLUMNS(Table3, "a", Table3[Source.Name])
)

Answer 2

Just another solution to use less memory:

UNION(
    DISTINCT(Table1[Source.Name]), 
    DISTINCT(Table2[Source.Name],
    ...
)