Debugging with vague error messages

Anonymous · ‎09-21-2023

I'm building a data model from a postgres database for a PowerBI project. I'm somewhat experience in PowerBI and Power Query but still struggle for hours trying to figure out issues where I get vague details. For example, I'm importing a table from postgres. When I apply the changes, it starts importing rows from the database but then eventually get an error

"OLE DB or ODBC error: [Expression.Error] The parameter is expected to be of type Text.Type or Binary.Type.."

My question is not specifically about this error but...what parameter is expected to be of type....? Any clues that could help pinpoint the issue? This seems to be a common occurrence when working with PowerBI and Power Query is vague errors that leave you playing guessing games for hours before stumbling across the problem. Are there other tools or methods that can help with debugging Power Query errors?

Anonymous · ‎09-25-2023

Hi @Anonymous ,

Regarding the error message you mentioned, “OLE DB or ODBC error: [Expression.Error] The parameter is expected to be of type Text.Type or Binary.Type,” it indicates that a parameter in your Power Query is expected to be either of type Text.Type or Binary.Type.

To troubleshoot this error and similar ones, here are some general steps you can take:

Review the Query Steps: Carefully examine each step in your Power Query to identify any potential issues. Pay attention to transformations, data types, and any applied functions that might be causing conflicts.

Check Data Types: Ensure that the data types of your columns match the expected types in subsequent steps. Mismatched data types can lead to errors.

Inspect Source Data: Verify the data in your PostgreSQL table and check for any anomalies or unexpected values that might be causing conflicts during import.