Location for tnsnames.ora :ĥ.Check for global_name settings with SQL. Make sure that the service name we are using is the same for which the listener is listening for.Ģ.The Entry is wrong in tnsnames.ora fileģ.tnsnames.ora is in wrong ORACLE_HOME locationĤ.Your Service name might have an alias.Check that in global entries as well as local entries. tnsnames.ora.įollowing needs to check to resolve this error :ġ.The Service name entry is missing from tnsnames.ora So If this error will come then DBA or developer needs to do first check i.e. In above situations this error will occur.There should be multiple reasons for this error.The following should be the reasons of this error. Just after installing the oracle database and tries to connect system user. When one database will try to connect with other database via database link. When Application tries to connect with database. ORA-12154 error is very common error related to ‘tnsnames.ora’ file.This error will come when oracle is unable to locate the service name specified in ODBC data source.ORA-12154 error will come at local service when application tries to connect with remote server.This error will come in following situations : The error is displayed in the above images.ĬLICK HERE FOR CHECKING DIFFERENCE BETWEEN SQL AND NOSQL Why ORA-12154 error will come? “ORA-12154 error has been searched on google approximately 1 lakh times per month” In this article i will explain how ORA-12154 error will solve and why this error will come.This is the most common error and most searched error by developers and DBAs.This error will come while trying to establish connection first time.So this is most common error in oracle. While working with different functionalities the oracle developers are facing different types of errors.The most common error coming while connecting database is ORA-12154: TNS:could not resolve the connect identifier specified. ORA-12154: TNS:could not resolve the connect identifier specified :