Oracle connection string without tnsnames.ora file
Starting with 10g clients, you can use the EZCONNECT feature, which does not require to edit the TNSNAMES.ORA file : username/password@servername:port/instance. For instance :
Data Source=localhost:1521/XE;Persist Security Info=True;User ID=scott;Password=tiger;Unicode=True
http://www.connectionstrings.com/oracle
This is a great resource
SERVER=(DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=MyHost)(PORT=MyPort))
(CONNECT_DATA=(SERVICE_NAME=MyOracleSID)));uid=myUsername;pwd=myPassword;
is what you want i believe...