Skip to main content
cancel
Showing results for 
Search instead for 
Did you mean: 

Find everything you need to get certified on Fabric—skills challenges, live sessions, exam prep, role guidance, and more. Get started

Reply
EllianHs
Regular Visitor

PowerBi Append two table with error message "Expression.Error: The field 'xxx' already exists

Hi 

 

I started getting errors this week (3/13/2023) when processing append tables in power query.

The message descrinbes there is a certain field has exist but from my understadning, when appending two tables, there shouldn't

has such limitatioion. Anyone could share some light what might go wrong? Capture.PNG

Ellian

1 ACCEPTED SOLUTION

Does adding Table.StopFolding(<<table>>) around both tables still result in an error?

I.e.

Table.Combine({Table.StopFolding(<<table>>), Table.StopFolding(<<table>>)})

 

Also, what version of Power Bi (or Excel) are you using?

View solution in original post

9 REPLIES 9
wdx223_Daniel
Super User
Super User

it seems the error comes from those two tables

artemus
Employee
Employee

What is your data source type?

While this is probably a bug with the way the data source does combine, it is probably caused by a different casing between the two columns.

The data source is data flow. It actually was acting fine but one day the dataset for the report refresh failed and has the error. If I removed the columns throw out the erros, it will just show the next column giving the errors

Does adding Table.StopFolding(<<table>>) around both tables still result in an error?

I.e.

Table.Combine({Table.StopFolding(<<table>>), Table.StopFolding(<<table>>)})

 

Also, what version of Power Bi (or Excel) are you using?

Hi @artemus,

 

I've stumbled across this while trying to solve this very issue.

I was doing a very simple Table.Combine() with two Dataflows and it was throwing an error that made no sense.

 

Can you explain this solution and what has changed to cause this to be needed?

Do I need to go and check other Datasets that have this Table.Combine() logic?

 

Thanks.

Have I solved your problem?
Please click Accept as Solution so I don't keep coming back to this post, oh yeah, others may find it useful also ;).
chrome-9xf-Zagzel-B

If you found this post helpful, please give Kudos.
It gives me a sense of instant gratification and, if you give me Kudos enough times, magical unicorns will appear on your screen.
If you find my signature vaguely amusing, please give Kudos.
KIfp67uy-Sr
Proud to be a Super User!PBI-Super-User-Rank-30x30-1x

If this works it indicates there is a bug in the datasource folding implementation (or less likely the power query engine). This funcation forcable breaks folding and as a result works around the bug.

It did work.

The Datasource is Dataflows using the PowerPlatform.Dataflows() connector in my case.

I wasted 3 hours thinking I was doing something wrong, so was glad to find this post. 

Would love to know what has changed and whether this will potentially break existing Datasets.

 

Have I solved your problem?
Please click Accept as Solution so I don't keep coming back to this post, oh yeah, others may find it useful also ;).
chrome-9xf-Zagzel-B

If you found this post helpful, please give Kudos.
It gives me a sense of instant gratification and, if you give me Kudos enough times, magical unicorns will appear on your screen.
If you find my signature vaguely amusing, please give Kudos.
KIfp67uy-Sr
Proud to be a Super User!PBI-Super-User-Rank-30x30-1x

I would also like to know, but haven't been able to reporduce this problem.

Yes, it works !! :). I have Version: 2.114.864.0 64-bit (February 2023).

Helpful resources

Announcements
Europe Fabric Conference

Europe’s largest Microsoft Fabric Community Conference

Join the community in Stockholm for expert Microsoft Fabric learning including a very exciting keynote from Arun Ulag, Corporate Vice President, Azure Data.

Power BI Carousel June 2024

Power BI Monthly Update - June 2024

Check out the June 2024 Power BI update to learn about new features.

PBI_Carousel_NL_June

Fabric Community Update - June 2024

Get the latest Fabric updates from Build 2024, key Skills Challenge voucher deadlines, top blogs, forum posts, and product ideas.

Top Solution Authors
Top Kudoed Authors