BUG - DirectQuery with Advanced Options

[raphael_moreira]

Hello. I have a scenario with problems:

Scenario 1
- I created a new data source in "DirectQuery" mode;
- I chose a "Table" from the list;

- I didn't use "Advanced Options" (default)
- After import, I added custom columns.
- Everything is OK!

Scenario 2
- I created a new data source in "DirectQuery" mode
- I expanded "Advanced Options", and typed my own query
- After import, I added custom columns;
- A warning pops up on the screen, does not let me save, and says it can only save if I change from "DirectQuery" to "Import".

- I don't want to do that!

Scenario 3
- I created a new data source in "DirectQuery" mode
- I chose a "View" from the list, which does the same query I did in Scenario 2;

- I didn't use "Advanced Options" (default)
- After import, I added custom columns;
- Everything is OK!

Why can't type my own query in "Advanced Options" and create custom columns?

It's the same thing I did in Scenario 1 and 3. And both worked with "DirectQuery" and custom columns.

Thank you.

[v-jiascu-msft · Accepted solution]

Hi @raphael_moreira,

I think that's the limitations of data transformations of DireatQuery. Please refer to #limited-data-transformations. 

If you open the SQL Server profiler, you will see the difference between a View and a customized query. 

If you have any more questions, please feel free to input here.

>>>Any such transformation will need to be applied on every query to the underlying source, rather than once on data refresh, so they are limited to those transformations that can reasonably be translated into a single native query. If you use a transformation that is too complex, then you will receive an error that either it must be deleted, or the model switched to Import mode.

Best Regards,

Dale