Forum Discussion
Redshift and data folding error
I am using a redshift database, and I can connect to that OK in Power BI Desktop. My problem comes when I try to use some calculated fields; I have simplified some down to try and find the error so for example:
Measure 2 = COUNT(evhc[flag])
Where flag is an integer. This give the error:
OLE DB or ODBC error: [Expression.Error] We couldn't fold the expression to the data source. Please try a simpler expression.
I assume that when folding this query that Power BI is using SQL syntax rather than Redshift?
Is this a bug or am I missing something?
p.s. I know I can do this without using a measure, but this is a test as my measures are more complex than this.
DrBiker I'm assuming you are connecting to RedShift in DirectQuery mode. This error is thrown when some aggregation (in this case the count) is been translated to M for execution, so it's not really SQL yet.
I think this is related to a bug that we know about, is [flag] a nullable column? Counting on nullable column wasn't working in the preview bits, we will be fixing it in the next release.
5 Replies
Redshift is in preview mode, so I guess it is a bug. Send a frown using the desktop frown so the developers can look at it.
DrBiker I'm assuming you are connecting to RedShift in DirectQuery mode. This error is thrown when some aggregation (in this case the count) is been translated to M for execution, so it's not really SQL yet.
I think this is related to a bug that we know about, is [flag] a nullable column? Counting on nullable column wasn't working in the preview bits, we will be fixing it in the next release.
Has this been resolved?
