I am able to connect to an Oracle database using several tools, but am unable to connect using Toad for Oracle 8.5.3 (though before a login/logout to Windows I was able to).
I am not using TNSNAMES.ORA to connect. I have two Oracle homes:
C:\Oracle\product\10.2.0\client_1 (OraClient10g_home1)
andC:\Oracle\product\10.2.0\client_2
(ODACHome2)
where client 2 was installed after client 1.
I have tried Toad with each home, but I get "ORA-12154: TNS:could not resolve the connect identifier specified" when I supply the database name, user name, and password. I can connect using SQL*Plus using this same information, and I can connect via ADO.NET (ODP.NET). tnsping (client 2) to the server works, but tnsping (client 1) does not.
My PATH environment variable contains, in order:
C:\oracle\product\10.2.0\client_2\bin;C:\oracle\product\10.2.0\client_1\bin
and changing the order of PATH seems to have no effect. When I added the line
NAMES.DIRECTORY_PATH= (LDAP, TNSNAMES)
to sqlnet.ora of client 2, Toad still could not connect, but the error message appeared much more quickly.