Error code
Oracle ORA-12154
ORACLEORA-12154
Database Error Code· An error code returned by a database server such as PostgreSQL or MySQL.
What it means
TNS could not resolve the connect identifier specified — connection descriptor not found.
How to fix it
- Verify the service name or net service name in tnsnames.ora and confirm the file is in the correct location (TNS_ADMIN).
- Use the full Easy Connect string format (host:port/service_name) to bypass tnsnames.ora.
- Check that the TNS_ADMIN environment variable points to the correct directory containing tnsnames.ora.
Not affiliated with Oracle. Answer summarized from the manufacturer's manual linked above; consult that source for the authoritative procedure.
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