this is error ORA-12154: TNS:could not resolve the connect identifier specified?
ORA-12154: TNS:could not resolve the connect identifier specified?
In case the TNS is not defined you can also try this one:
If you are using C#.net 2010
or other version of VS and oracle 10g express edition or lower version, and you make a connection string like this:
static string constr = @"Data Source=(DESCRIPTION=
(ADDRESS_LIST=(ADDRESS=(PROTOCOL=TCP)(HOST=yourhostname )(PORT=1521)))
(CONNECT_DATA=(SERVER=DEDICATED)(SERVICE_NAME=XE)));
User Id=system ;Password=yourpasswrd";
After that you get error message ORA-12154: TNS:could not resolve the connect identifier specified
then first you have to do restart your system and run your project.
And if Your windows is 64 bit then you need to install oracle 11g 32 bit and if you installed 11g 64 bit then you need to Install Oracle 11g Oracle Data Access Components (ODAC) with Oracle Developer Tools for Visual Studio version 11.2.0.1.2 or later from OTN and check it in Oracle Universal Installer Please be sure that the following are checked:
Oracle Data Provider for .NET 2.0
Oracle Providers for ASP.NET
Oracle Developer Tools for Visual Studio
Oracle Instant Client
And then restart your Visual Studio and then run your project .... NOTE:- SYSTEM RESTART IS necessary TO SOLVE THIS TYPES OF ERROR.......
The database must have a name (example DB1), try this one:
OracleConnection con = new OracleConnection("data source=DB1;user id=fastecit;password=fastecit");
In case the TNS is not defined you can also try this one:
OracleConnection con = new OracleConnection("Data Source=(DESCRIPTION=(ADDRESS_LIST=(ADDRESS=(PROTOCOL=TCP)(HOST=localhost)(PORT=1521)))(CONNECT_DATA=(SERVER=DEDICATED)(SERVICE_NAME=DB1)));
User Id=fastecit;Password=fastecit");
run the below command in command prompt
tnsping Datasource
This should give a response like below
C:>tnsping *******
TNS Ping Utility for *** Windows: Version *** - Production on *****
Copyright (c) 1997, 2014, Oracle. All rights reserved.
Used parameter files: c:\oracle*****
Used **** to resolve the alias Attempting to contact (description=(address_list=(address=(protocol=tcp)(host=)(port=)))(connect_data=(server=)(service_name=)(failover_mode=(type=)(method=)(retries=)(delay=))))** OK (**** msec)
Add the text 'Datasource=' in beginning and credentials at the end. the final string should be
Data Source=(description=(address_list=(address=(protocol=tcp)(host=)(port=)))(connect_data=(server=)(service_name=)(failover_mode=(type=)(method=)(retries=)(delay=))));User Id=;Password=;**
Use this as the connection string to connect to oracle db.