hey man,
just create the keys for using the below code. you just change the ServerName key value where the database is located.
code is below,
strServer= ConfigurationManager.AppSettings["ServerName"].ToString();
strDatabase= ConfigurationManager.AppSettings["DataBaseName"].ToString();
strUserID= ConfigurationManager.AppSettings["UserId"].ToString();
strPwd= ConfigurationManager.AppSettings["Password"].ToString();
report.DataSourceConnections[0].SetConnection(strServer, strDatabase, strUserID, strPwd);
please let me know if you have any doubt