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Regular Visitor

Append Queries as New will result in no query folding

Dear fellow BI'ers,


I have a really strange behaviour when appending queries as new.


In my scenario, I have one source (SQL Server) to whom I connect. This source has several companies within it. Always with CompanyName$TableName as the table name. I then filter the tables to show me only a specific table. Lets say Sales. I will get a list of the Sales table from all companies. I will add those to my Queries with "Add as New Query". Afterwards, I will delete the filter step between Source and Navigation. Then, I will add a column called Company with the respective company name. Until now, I can see the native query.


If I then take the first query and click on "Append Queries as New" and append all of them together, the new Source will not be able to show me the native query. To confirm, that no query folding occurred, I will make diagnostics. This confirms that there is no query folding.


When I take the first query and click "Append Queries" and take exactly the same queries, query folding works.


This is new behavior that I haven't seen before. Can you help me how this happens and how this can be changed???




Super User III
Super User III

Compare the generated M code between the two approaches. 


Append as new:

Source = Table.Combine({FirstTable, SecondDTable})


Append :

#"Appended Query" = Table.Combine({ThisTable, OtherTable})


So - technically there's no difference.  Maybe query folding doesn't like to work with references only.


Having said all this - have you considered doing the UNION ALL at the source, ie with a custom SQL query?


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