Instance as a parameter in MS SQL DB Connection

Hi KNIMEers ,

I am facing an issue connecting to MS SQL Server .
Its weird , i am able to connect to MS SQL server where the instance name is default “i.e SQL Express”
But i am facing an IOException error when i try to connect to MS SQL with an instance name which is not default.
I am guessing its because of the instance. All the permissions are granted and the ports are open still i am unable to connect.
How to pass instance as a parameter in DB node, what is the syntax ?
Please help.

Hi @Suhas,

A few questions…

Are you using the Microsoft SQL Server Connector node or the DB Connector node to connect to the database?

Which jdbc driver are you using?

Are you able to post a screenshot of your connection config (any private details should be redacted), and what is the exact error you are getting?

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Yes i am using MS SQL connector node


Your immediate help is appreciated.

I have tried with officail driver as well, but there get a totally different error with respect to " instance running check or firewall check".


Thanks @Suhas.

Is your SQL Server database running on a different machine to where you are running Knime?

You said you can connect to it with the default instance name of SQL Express, but not when it is a different instance name…

I think instance name on SQL Server can be passed as a parameter on the jdbc driver. In which case you could try adding “instance” as a jdbc parameter on the node, as shown here:


Yes, the SQL Server DB is on different machine.

Passed instance name as parameter and it works. Thanks for that. So this is on jTDS driver.

If I try to connect with official driver this is the error "Execute failed: The TCP/IP connection to the host, port 1433 has failed. Error: “Connection refused: connect. Verify the connection properties. Make sure that an instance of SQL Server is running on the host and accepting TCP/IP connections at the port. Make sure that TCP connections to the port are not blocked by a firewall.”.
Firewall is not blocking and all Port numbers are correct.
Not sure of the error though.


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Hello @Suhas,

maybe this post helps:


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