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

The Fabric community is upgrading! Read all of the details including the timeline and what you can expect. Learn more

Reply
cflynn_29
Helper I
Helper I

Dynamically Rename 1st Column

I am trying to dynamically rename the 1st column from whatever its Number value is to just "Column1"

 

cflynn_29_1-1674767181216.png

 

From here i use = Table.ColumnNames(#"Promoted Headers") to get the column names as a list.

cflynn_29_2-1674767247492.png

 

From there i only want the first item in the list so i use List.FirstN(Custom1,1)  and that gets me the 1st item which is the first column name

cflynn_29_3-1674767341645.png

 

Now i want to rename that column in the #"Promoted Headers" table/step so i tried

= Table.RenameColumns(#"Promoted Headers", #"Kept First Items", Column1) and this is what i get

 

cflynn_29_4-1674767891990.png

 

Not sure if i am using the function incorrectly some help would be great.

 

And here is the Mcode

#"Promoted Headers" = Table.PromoteHeaders(#"Transposed Table5", [PromoteAllScalars=true]),
Custom1 = Table.ColumnNames(#"Promoted Headers"),
#"Kept First Items" = List.FirstN(Custom1,1),
Custom2 = Table.RenameColumns(#"Promoted Headers", #"Kept First Items", Column1),

 

Thank you,

1 ACCEPTED SOLUTION
wdx223_Daniel
Community Champion
Community Champion

Custom2 = Table.RenameColumns(#"Promoted Headers", #"Kept First Items"&{“Column1"})

View solution in original post

3 REPLIES 3
wdx223_Daniel
Community Champion
Community Champion

Custom2 = Table.RenameColumns(#"Promoted Headers", #"Kept First Items"&{“Column1"})

ImkeF
Community Champion
Community Champion

Hi @cflynn_29 ,
well done, you are on the right path here. Just put the new name into quotes ("") like so:

 

Custom2 = Table.RenameColumns(#"Promoted Headers", #"Kept First Items", "Column1"),

 

 

Imke Feldmann (The BIccountant)

If you liked my solution, please give it a thumbs up. And if I did answer your question, please mark this post as a solution. Thanks!

How to integrate M-code into your solution -- How to get your questions answered quickly -- How to provide sample data -- Check out more PBI- learning resources here -- Performance Tipps for M-queries

Got a slightly new error here, is it because the original column name is being represented as a number and not a text value?

cflynn_29_0-1674774494373.png

 

Helpful resources

Announcements
FabCon and SQLCon Barcelona 2026

FabCon & SQLCon – Barcelona 2026

Join us in Barcelona for FabCon and SQLCon, the Fabric, Power BI, SQL, and AI community event. Save €200 with code FABCMTY200.

Power BI DataViz World Championships carousel

Power BI DataViz World Championships - June 2026

A new Power BI DataViz World Championship is coming this June! Don't miss out on submitting your entry.