Hi @grzegorzZF, and welcome to the forum!
I would recommend using the dedicated Oracle Connector rather than the DB Connector, but having said that, both should work, so it does look like you still have a config error somewhere.
Here is what a demo connection I have created locally looks like when using DB Connector
and the equivalent using the Oracle Connector node
I’ve just obfuscated my server name, but the remainder of the info here is purely for my demo db, so I’ve left intact so you can compare with the format you are using.
Some questions:
- Which version of Oracle are you using?
The message you are getting typically indicates an issue with the port number (see my list of errors at the end), but it might indicate that an Oracle service isn’t running, or that the TNS Listener isn’t configured correctly… so…
-
Can you connect to the database from the same PC (or any other PC) using any other application, such as SQL Developer?
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Is your Oracle database running on the same machine, or is it on a remote server?
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Are you using a tnsnames.ora file to resolve the connection to the database? If so, it’s possible there is an error in it (although that’s unlikely if other applications can connect from the same pc.)
Perhaps you can show your config screen (with any sensitive information changed, but such that we can still see how the information is formatted)
For info, I tried various ways of “breaking” my connection, and below is the results. Of all the different “mistakes” when using the Oracle Connector, only incorrect port number seemed to produce the “could not establish the connection” error, although with the DB Connector, the “could not establish connection” error appears to occur if either the port, or the host server are incorrect, although I did get a few variable results
Entering wrong host name:
ERROR DB Connector 8:10 Execute failed: IO Error: Unknown host specified
Entering incorrect service/database name
ERROR DB Connector 8:10 Execute failed: Listener refused the connection with the following error:
ORA-12514, TNS:listener does not currently know of service requested in connect descriptor
Entering incorrect parameter format
e.g. @servername:port:databasename
instead of @servername:port/databasename
ERROR DB Connector 8:10 Execute failed: Listener refused the connection with the following error:
ORA-12505, TNS:listener does not currently know of SID given in connect descriptor
Incorrect Port Number or Incorrect host name along with invalid format - such as using “:” instead of “/” before database name
ERROR DB Connector 8:10 Execute failed: IO Error: The Network Adapter could not establish the connection