Expression.Error: We cannot apply operator & to types Number and Record

[xixo221]

What do I want?

I would like to create veeeery basic dataflow and report/dashboard/whatever just to verificate the proof of concept, because my company is currently evaluating which reporting solution to use.

How did I get here?

I used PowerBI service for the first time (currently in free trial version). I did not fiddle with any settings.

1) Created and connected my on-premise data gateway to PBI

2) In my workspace I created new dataflow

3) selected data source for my dataflow

(I also checked Navigate using full hierarchy option in advanced options)

4) selected a few tables (doesnt matter which) and clicked Create. As you can see the connection with gateway is working as I can see the DB data.

As you can see I am not doing any transformations. I only selected tables and published dataflow right after.

5) I click on publish button

6) Dataflow gets published and starts to refresh right after, but it always fails in the end (takes roughly 5 minutes).

(btw Error message is partially in my local language even though I explicitly set PowerBI language to english)

Here is the error msg (I translated non english parts to english):

sale_order: Error Code: Mashup Exception Expression Error, Error Details: Couldn't refresh the entity because of an issue with the mashup document MashupException.Error: Table insertion failed., InnerException: We cannot apply operator & with types Number a Record., basic error: We cannot apply operator & with types Number a Record. Details: Reason = Expression.Error;Message = We cannot apply operator & with types Number a Record.;Detail = [Operator = "&", Left = 2, Right = [...]];Microsoft.Data.Mashup.Error.Context = System

I tried this multiple times even with different tables. But it always fails. (failing tables change).

I honestly dont understand the error at all. I didnt do any transformations and I dont have any Record type columns in my tables.

And the even weirder thing is that if I have only two tables (even if it were two tables that failed beforehand) in my dataflow then everything works, but as soon as I add more than 2, then I get the error.

Additional info

Database (Postgres 15) and data gateway are on the same computer. DB runs in docker with forwarded ports.

You can see here that I dont have any Record type columns.

[mrozzano]

@xixo221, our issue might be related to this :

Solved: Re: Dataflow Gen2 Start to fails after Enterprise ... - Microsoft Fabric Community

[mrozzano]

I started getting this same error, too.

I did some on-demand refreshes a few minutes apart for a simple dataflow. The failures appear random, but all have the same error (listed at the bottom).

The tables listed above are a duplicate and reference of a table that pushes to a lakehouse. I wasn't sure if the dataflow failed because the tables were reference tables vs duplicate tables so i created both types to test. But, it doesn't matter. As the screen shots show, either or both can fail randomly. 

When I disable staging on these tables, the dataflow refreshes successfully. However, that means I can't use Get data > Dataflows to select these tables, defeating the purpose of "Enable staging".

This dataflow refreshed without errors previously. Is something broken behind the scenes or am I doing something wrong ? 

Error Code: Mashup Exception Expression Error, Error Details: Couldn't refresh the entity because of an issue with the mashup document MashupException.Error: Failed to insert a table., InnerException: We cannot apply operator & to types Number and Record., Underlying error: We cannot apply operator & to types Number and Record. Details: Reason = Expression.Error;Message = We cannot apply operator & to types Number and Record.;Detail = [Operator = "&", Left = 2, Right = [...]];Message.Format = We cannot apply operator #{0} to types #{1} and #{2}.;Message.Parameters = {"&", "Number", "Record"};Microsoft.Data.Mashup.Error.Context = System GatewayObjectId: ____ (Request ID: ____).

[Greg_Deckler]

@xixo221 This seems very much like a bug or some weird limitation with Postgres. I would submit it to the Issues forum: https://community.fabric.microsoft.com/t5/Issues/idb-p/Issues