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ChemEnger
Advocate IV
Advocate IV

Table.DuplicateColumn ColumnType ignored

I have used a Table.DuplicateColumn command to create a copy of a datetime column (Start DateTime), including specifying the type as date:

#"Duplicated Start DateTime" = Table.DuplicateColumn(#"Previous Step", "Start DateTime", "Start Date", type date)

My question / issue is that the ColumnType option seems to be ignored and the new column appears as datetime (although the 'icon' is date), which I then have to change in another step.

Original columns:

ChemEnger_0-1724921017733.png

New Column:

ChemEnger_1-1724921031438.png

 

1 ACCEPTED SOLUTION
lbendlin
Super User
Super User

Might be just a cosmetic issue, similar to what we had for the longest time with Table.AddColumn *

 

Note: Specifying a Date column type is futile as Power BI doesn't actually have such a data type.  In Power BI everything is datetime behind the scenes.

 

* on second thought you can replace Table.DuplicateColumn with Table.AddColumn.

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3 REPLIES 3
lbendlin
Super User
Super User

Might be just a cosmetic issue, similar to what we had for the longest time with Table.AddColumn *

 

Note: Specifying a Date column type is futile as Power BI doesn't actually have such a data type.  In Power BI everything is datetime behind the scenes.

 

* on second thought you can replace Table.DuplicateColumn with Table.AddColumn.

Table.AddColumn(#"Previous Step", "Start Date", each Date.From([Start DateTime]), type date)
Did the job equally as well - in which case, what's the benefit of DuplicateColumn and the (optional) ColumnType?!

It's what we call "syntax sugar" - a convenience function that is equivalent (or should be) to a more atomic function.

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