Error when trying to log in: ORA-12154

Question

I am using Oracle 10g and PL/SQL Developer for the development. I have already tested from Net Manager that the database can be connected to, but when I tried to connect with PL/SQL Developer there was problem that I do not understand:

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

I have already searched for solution for the problem but still it can't be resolved. Any advice?

Answer 1

This was a hard one. tnsping works. tnsnames.ora is correct. This post solved it for me: http://sambitimes.blogspot.de/2010/10/ora-12154-error-in-windows-7.html

If installation path of PL/SQL-Developer contains brackets, it screws up... This will not work with win7: "C:\Program Files (x86)\PLSQL Developer"

this does for me: "C:\Program Files\PLSQL Developer"

I hope it helps for others.

Answer 2

That usually means that the database name you specify is not in the tnsnames.ora file. If you open PL/SQL Developer you will find the option "support info" under the About menu. This has an entry such as this:

TNS File
  D:\Oracle\Designer\net80\admin\tnsnames.ora

Make sure your database is in this file.

Answer 3

Oracle documentation says:

Cause: A connection to a database or other service was requested using a connect identifier, and the connect identifier specified could not be resolved into a connect descriptor using one of the naming methods configured. For example, if the type of connect identifier used was a net service name then the net service name could not be found in a naming method repository, or the repository could not be located or reached.

Are you trying to connect to the database the same way from Net Manager and PL/SQL Developer?