DirectQuery + TMDL: Column type changes to double after refresh

[P108]

Hi,

I’m using DirectQuery to SQL Server.

In the source, the column is already defined as "decimal(38,3)". However, in Power BI it appears as "double".

        column exampleNumber

            dataType: double

            sourceProviderType: decimal(38, 3)

            lineageTag: 

            summarizeBy: sum

            sourceColumn: exampleNumber

            annotation SummarizationSetBy = User

When I change it to "decimal" in TMDL and apply, it works initially. After refresh, it reverts back to "double".

Is there any way to persist the correct "decimal" type in the model?

Thanks!

[MFelix · Accepted solution]

Hi @P108 ,

When using TMDL to update DQ or DL there may be the need to use a changedproperty option to apply the changes due to the DQ format. after the specific column add the following code:

		column exampleNumber
			dataType: decimal
			sourceProviderType: decimal(38, 3)
			lineageTag: 
			summarizeBy: sum
			sourceColumn: exampleNumber

		changedProperty = DataType

		annotation SummarizationSetBy = User

This should make the proper change to the semantic model and make it persistent be aware that the DataType is case sensitive so do it exactly has is.

If you need to update other type of information that comes from the DQ table you need to add a changedProperty per each property and at the level you need.