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OLE DB or ODBC error: [Expression.Error] Local evaluation of join with key equality comparers

Hi PBI Community, 


I'm currently stuck with the following error: 

Screen Shot 2020-02-20 at 3.00.33 pm.png



I am attempting to create a report in PBI Desktop (February 2020) with a DirectQuery connection to a PostgreSQL database. I have 5 tables within the report (a centralised Date table and 4 e-commerce data tables, all of which have a Date column). I am able to build visualisations within the report with data from the various tables individually without any problems but when I make a relationship in the data model between the DateTime table and any of the e-commerce tables (necessary) I get the above error. 


Trouble-shooting thus far

Trawling through the interwebs, some posts have vaguely suggested that this error may be due to trying to join mixed data types (I can confirm all of the Date columns I'm trying to relate are of the same underlying format) or joinAlgorithms (I don't have any table joins or merges, as far as I am aware)(@ImekF solved this one, might be able to help here?).


I am at a loss.  I include below a sample of data for each table.


Date table

Screen Shot 2020-02-20 at 3.21.20 pm.png





E-commerce tables follow same format as below

Screen Shot 2020-02-20 at 3.28.45 pm.png


Hopefully someone can help, and many thanks in advance!

Super User III
Super User III

Re: OLE DB or ODBC error: [Expression.Error] Local evaluation of join with key equality comparers

Hi @nkh ,


I always try to avoid DirectQuery mode or reduce it to simple queries.

Hence my questions:

- Do you really need DirectQuery mode?

- Can you merge the queries with SQL beforehand?


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Frequent Visitor

Re: OLE DB or ODBC error: [Expression.Error] Local evaluation of join with key equality comparers

Hi @mwegener ,

Thanks for your reply.


The purpose of this report is to provide near-real-time-data to stakeholders in our business, and given that we are using Pro licences (read: 8 times/day refresh not timely enough), DirectQuery is necessary. 


I will look into the viability of combining the data into one SQL query but if we can find a PBI solution or at least an explaination for why this error is occurring that'd be great. 🙂 

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