Windows 10 Professionnel
Power Bi Desktop 2.91.884.0 64-bit
MariaDB Server 10.5.9
MariaDB Connector C 3.1.12 64 bits
MariaDB Connecteur ODBC 3.1.11 64 bits

Moved from CONC to CONODBC.

Thank you for your report!

Could you please generate ODBC trace for the error you observe with your application and attach it here?
Thank you in advance!

Hi Lawrin,

You'll find the ODBC trace, attached to this mail.

But I'm surprised because I was expecting direct access to MariaDB, and I
see that ODBC is involved. And everybody knows (think?) that ODBC is rather
slow...

So the question could be: why not use an ODBC connection instead of MariaDB
(I've tried and it's working).

Not sure I would be able to explain this to my customer....
...Who is already rather unhappy because the POC isn't moving fast enough...

Regards,

Louis

Le lun. 12 avr. 2021 à 11:55, Lawrin Novitsky (Jira) <jira@mariadb.org> a

Thanks for the trace, I'll take a look.
"So the question could be: why not use an ODBC connection instead of MariaDB
(I've tried and it's working)." - what do you mean? You said ODBC connection is used, and that's why you are, actually, here.

Pls have a look at the attached file.
When obtaining Data in Power Bi, I specify MariaDB as the source, and a
direct access.

The error message tells in english "OLE DB or ODBC error:
[Expression.Error] We couldn't fold the expression to the data source".

But from my understanding, once more, I'm trying to use a direct access to
MariaDB.

Hope this clarifies?

Regards

Louis

Le mar. 13 avr. 2021 à 12:33, Lawrin Novitsky (Jira) <jira@mariadb.org> a

Ah, you mean direct ODBC driver linking omitting driver manager? I'd imagine they mean under "Direct Access" something else there.

At first look at your trace - I can see successful query on 2021Total field - that is something like select sum(2021Total) from <table>, and that is the last thing in the trace. I can't see an attempt to query anything from Commercial field. Looks like error generated not by ODBC driver.
The only reference of that name in the table structure request. There is nothing suspicious there. Does what you tried to do work with other data sources?

I've been able to do the same thing when using an ODBC connection to the
MariaDB table.

However, when searching in Google, I've found in the Microsoft Power Bi
site that Direct access is not supported for MySQL.
It seems to be supported for MariaDB..
Power BI Data Sources ==> Power BI data sources - Power BI | Microsoft Docs
<https://docs.microsoft.com/en-us/power-bi/connect-data/power-bi-data-sources>

On the other hand, some guys are speaking about a Power BI trace. I'll try
to figure out if I can activate this trace...

Le mer. 14 avr. 2021 à 11:01, Lawrin Novitsky (Jira) <jira@mariadb.org> a

Hello Lawrin,

Finally, I found the solution on a Google thread: the column Commercial was
defined in MariaDB as TEXT. I changed it to VARCHAR, and everything runs
smoothly.
Pls have a look there ==>
https://community.powerbi.com/t5/Issues/OLE-DB-or-ODBC-Error-Expression-Error-We-couldn-t-fold-the/idi-p/630511

From my point of view, we can close the ticket.

Once again, thank you for your patience and your help

Best regards

Louis

Le mer. 14 avr. 2021 à 19:26, DELEDALLE Louis (Jira) <jira@mariadb.org> a