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


Problem 

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

Cause

Problem with the connection configuration or the specified connect identifier.

Possible Resolution

Verify that the TNSNAMES.ORA exists and is accessible.

Make sure that there are no syntax errors in TNSNAMES.ORA.

Verify that the connection string is correct.

Verify if there are any DNS issues.

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