OLE DB or ODBC error

[Rbakker888]

Hi, so today I tried to add a new table to PowerBI only instead it started giving me a lot of errors on older tables. I managed to get rid of most of them now but am now stuck at the one below:

Its giving this error for about every single table I am trying to refresh but the odd thing is that in the power query editor, I can see it perfectly fine in the preview. The power query itself also does not display anything weird that could be causing this.

I am importing my data from a synapse SQL pool.

Another thing that might help is that when I try refresh my data, at a moment it open a second window for a 10th of a second and then it gives the error. No clue what this screen is though.

I tried searching other forums but wasnt able to find a solution that worked for me.

[v-csrikanth]

Hi @Rbakker888 
Thank you for being part of the Microsoft Fabric Community.
The error you're encountering, "OLE DB or ODBC error: Cannot display the data because Power BI can't determine the relationship between two or more fields," typically occurs when there are missing, ambiguous, or incorrectly defined relationships in your Power BI data model.

Start by reviewing your model to ensure all tables are correctly related using primary and foreign keys, and confirm there are no missing or mismatched relationships. Avoid circular or many-to-many relationships unless absolutely necessary, as they can confuse Power BI's ability to resolve the correct data path.

If you're using composite keys, make sure they are consistently implemented across your related tables. Alternatively, using surrogate keys can simplify your model and help avoid ambiguity.

Check that related columns have matching data types and avoid nulls or mismatches that could disrupt joins. Use the model view in Power BI to visually inspect how tables connect and ensure relationships are active and appropriate for your data logic.

Correcting these relationship issues should resolve the display error and allow your visuals to work as expected.

If the above information helps you, please give us a Kudos and marked the Accept as a solution.
Best Regards,
Community Support Team _ C Srikanth.

[Rbakker888 · Accepted solution]

Thank you for your assistance, eventually I managed to find the stupid mistake myself and that was that in a union I was doing, there was 1 singular column that switched with the one below it in the create function.

[Rbakker888]

let
Source = Sql.Database("ssynapseworkspace-ondemand.sql.azuresynapse.net", "DWH"),
dbo_fact_Melding = Source{[Schema="dbo",Item="fact_Melding"]}[Data],
#"Removed Columns" = Table.RemoveColumns(dbo_fact_Melding,{"MeldingGroepId", "Afspraken"})
in
#"Removed Columns"

That is the advanced query editor for one of the tables, all the others are exactly the same only most dont have removed columns.

[Rbakker888]

Another error I am getting on a different column that I removed to see if it was just that issue is the following:

<ccon>DataSource.Error: Microsoft SQL: Conversion failed when converting the nvarchar value 'Controle' to data type int.

I tried to find it but it should never convert it to a INT, as the data type for that column is also just text.