Add column to dataset --> How to update in semantic model?

[Enholz]

Hello,

After adding a new column to my dataset (let's call it TABLE) in PowerBI Service, I tried updating a semantic model to include this new column. After downloading the semantic model to desktop and opening it, I can refresh the whole model, but it adds a new table called TABLE 2, that does not contain all my previous measures & calculated columns. These metrics were kept on TABLE... 

Is there a way to either:

- Refresh and add the new column to the dataset TABLE without creating a new one called TABLE 2? 

- Migrate all previous calculations and measures quickly from TABLE to TABLE 2 without having to duplicate and rewrite everything? 

Thanks for your help! 

Enholz

[Deku · Accepted solution]

Don't quite understand what you are doing. 

But to copy measures between tables.

• Enable TMDL view in preview setting.
• Open the TMDL view tab.
• Drag the measures into the text editor.
• Remove the lineage tags and copy the measure definitions to clip board
• Drag your new table to a new TMDL view window and copy in the measures into the table definition and select apply.

[v-tsaipranay · Accepted solution]

Hi @Enholz 

Thank you for reaching out to the Microsoft Fabric Community.

To avoid creating TABLE 2, ensure you're simply refreshing the existing model in Power BI Desktop. After adding the new column in Power BI Service, in Power BI Desktop, go to Home Tab > Refresh. This will update TABLE directly without creating a new table. Ensure that you’re not re-importing the data as a new source.

If TABLE 2 was created, as @Deku  suggested to use TMDL for migrating measures is correct. Alternatively, you can copy-paste measures from TABLE to TABLE 2 directly in Power BI Desktop.

These steps should resolve both issues: updating your table with the new column and migrating your measures efficiently.

I hope this will resolve your issue, if you need any further assistance, feel free to reach out.

If this post helps, then please give us Kudos and consider Accept it as a solution to help the other members find it more quickly.

Thankyou.

[v-tsaipranay]

Hi @Enholz ,

May I ask if you have resolved this issue? If so, please mark the helpful reply and accept it as the solution. This will be helpful for other community members who have similar problems to solve it faster.

Thank you.

[v-tsaipranay]

Hi @Enholz ,

May I ask if you have resolved this issue? If so, please mark the helpful reply and accept it as the solution. This will be helpful for other community members who have similar problems to solve it faster.

Thank you.

[v-tsaipranay]

Hi @Enholz ,

I wanted to check if you had the opportunity to review the information provided. Please feel free to contact us if you have any further questions. If my response has addressed your query, please accept it as a solution and give a 'Kudos' so other members can easily find it. Also thank you @Poojara_D12 for your inputs.

Thank you.

[Poojara_D12]

Hi @Enholz 

This issue usually occurs when Power BI cannot match the existing table structure during a refresh—often due to schema changes or differences in data source queries. When Power BI Desktop detects a mismatch, it may treat the updated data as a new table, hence the creation of "TABLE 2". To avoid this and ensure the new column is added to the original "TABLE" without duplicating it, the best approach is to edit the Power Query (Transform Data) step rather than refreshing directly. Go into Power Query Editor, find the original "TABLE", and update the source query or step that defines the schema—ensuring it includes the new column. Once done, apply changes, and Power BI will append the new column to the existing table without creating a new one. If "TABLE 2" has already been created and contains the updated structure, but your measures and calculated columns are still in "TABLE", you can go into the Model view and manually copy the DAX formulas from "TABLE" and paste them into "TABLE 2". However, this is time-consuming and error-prone. Instead, it’s better to fix the schema alignment in the original "TABLE" so the model keeps its continuity, measures, relationships, and formatting intact. Avoid renaming or replacing the table directly, and ensure column names, types, and structure are consistent with previous versions when updating the source.

[Enholz]

Hello Poojara and thank you for answering,

It appears that connecting to the semantic model is only Live connection mode, and Power Query is not supported in Live connection mode. This explains why I wasn't able to use Power Query at all when I first tried to edit my dataset.

As you mentionned the other possibility is to copy DAX formuals manually and this is what I did, but it is quite tedious.

Enhol

[v-tsaipranay · Accepted solution]

Hello @Enholz ,

You are correct. In Live Connection mode, Power Query is not available, and schema changes must be handled at the source of the semantic model.

To update the existing table without creating a new one, you would need to modify the source model directly (add the new column in the source dataset), then republish it to Power BI Service.
This ensures all existing measures, relationships, and formatting are preserved without manual migration.

Currently, there is no native feature in Power BI Desktop to migrate measures automatically between tables in a Live Connection.

If this post helps, then please give us Kudos and consider Accept it as a solution to help the other members find it more quickly.

Thankyou.

[v-tsaipranay · Accepted solution]

Hi @Enholz 

Thank you for reaching out to the Microsoft Fabric Community.

To avoid creating TABLE 2, ensure you're simply refreshing the existing model in Power BI Desktop. After adding the new column in Power BI Service, in Power BI Desktop, go to Home Tab > Refresh. This will update TABLE directly without creating a new table. Ensure that you’re not re-importing the data as a new source.

If TABLE 2 was created, as @Deku  suggested to use TMDL for migrating measures is correct. Alternatively, you can copy-paste measures from TABLE to TABLE 2 directly in Power BI Desktop.

These steps should resolve both issues: updating your table with the new column and migrating your measures efficiently.

I hope this will resolve your issue, if you need any further assistance, feel free to reach out.

If this post helps, then please give us Kudos and consider Accept it as a solution to help the other members find it more quickly.

Thankyou.

[Deku · Accepted solution]

Don't quite understand what you are doing. 

But to copy measures between tables.

• Enable TMDL view in preview setting.
• Open the TMDL view tab.
• Drag the measures into the text editor.
• Remove the lineage tags and copy the measure definitions to clip board
• Drag your new table to a new TMDL view window and copy in the measures into the table definition and select apply.