The following exception is very common type of exception for .net developer and oracle user. ORA-12154:TNS:could not resolve the connect identifier specified Especially when you are using Oracle Data Provider for .Net and getting the above exception because of wrong connection string. So whenever you are using ODP you must following the connection string in the following pattern. string connString = "user id=*****;password=*****;data source=(DESCRIPTION=(ADDRES... IP Address or ......