Oracle ORA-12154 TNS: could not resolve the connect identifier specified

[ELIU]

Hi,

I have connected to our on-prem Oracle database from my Power BI desktop and run serval queries yesterday without issues. However, today when I tried to add another new query I got this ORA-12154 error. I have verified that:

1, I am on our organization's network

2, I have the most up to date tnsora file mapped

3, I have entered the correct credentials for the Oracle instance. 

I am wondering why the connection works for my other queries but not for this one. I am pulling the data from the same table and the only difference is the the filters. Any hints would be appreciated!

Thanks

[v-yangliu-msft]

Thanks for the reply from Sahir_Maharaj , please allow me to provide another insight: 

Hi  @ELIU ,

These errors might occur if the Oracle tnsnames.ora database connect descriptor is misconfigured, the net service name provided is misspelled, or the Oracle database listener is not running or not reachable, such as a firewall blocking the listener or database port. Be sure you are meeting the minimum installation prerequisites.

Ensure that the oracle client is installed correctly and that the strings are correct, verify that the tnsnames.ora file is configured correctly and that you are using the correct net_service_name. also make sure that the net_service_name is the same between the computer that is using Power BI Desktop and the one that is running the Gateway,. Specify the SID using the following format: ServerName/SID.

Refer to:

Manage your data source - Oracle - Power BI | Microsoft Learn

oracle - ORA-12154: TNS:could not resolve the connect identifier specified (PLSQL Developer) - Stack...

This is the related document, you can view this content:

Solved: New Error ORA-12154 TNS:could not resolve the conn... - Microsoft Fabric Community

Solved: Connect to Oracle Error - ORA-12154: TNS:could not... - Microsoft Fabric Community

Best Regards,

Liu Yang

If this post helps, then please consider Accept it as the solution to help the other members find it more quickly.

[Sahir_Maharaj]

Hello @ELIU,

Try connecting to the Oracle database using another tool (like SQL*Plus, SQL Developer, or a similar database tool) using the same TNS entry to determine if the issue is specific to Power BI or a more general connectivity issue.

I would also recommend reviewing the Oracle logs or enable Oracle Net tracing to get more detailed error information. This might provide an insight into why the connection is failing.

Hope this helps.