Could not create connection to MySql database server.

Hi Team,

I have connected to mysql db couple of days ago. but when i tried to connect it today, i got the error message as “Execute failed: Could not create connection to database server.”
I have gone through all the related topics in the forum, KNIME database extension guide, tried all possible ways, but still not successful.
Below are the screen shot details of node config, preferences and error log.
Could some help on this, as i am not sure where i am missing.


Hi there!

Have you went into KNIME log? Maybe there is more information.

Also KNIME already provides an MySQL database driver so there is no need to add additional one I think. Maybe it confuses KNIME for some reason. Delete it, restart KNIME and try again.


Hi Ivan,

I followed the steps provided by you, still no luck. Also here is the log.

KNIME Log.txt (3.9 MB)

The stack trace in your log shows a null pointer exception coming out of the mySQL driver code trying to assess the character set on the server; a number of StackOverflow discussions about this exception all seem to say “use the latest driver - this was fixed in 5.1.41”. I see in your above screenshot that the version shipping with KNIME is 5.1.39, so maybe download the latest?

Hi Quaeler,

Thanks for your time and suggestion. I am not sure how to update or download the specific jar file. Could you please provide me the steps on how to update from 5.1.39 to 5.1.41 if possible.
Mean while i did a work around, i have selected the connector jar file directly from MySQL folder, instead of KNIME plugins, it worked.
Thank you Ivan also for your time and assistance.



It sounds like your work around is already doing what i suggested; that you have a MySQL tar/zip which you downloaded from Oracle and unpacked, and that you’ve configured KNIME to reference the jar inside that unpacked folder.

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Hi Pavan!

Glad it works now :wink:


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