RODBC connectivity to Oracle without tnsnames.ora

Question

I am trying to connect to Oracle from R using RODBC without using tnsnanes.ora.

I have tried following strings, but none of them are working.

> con.text <- paste0("Driver={OracleODBC-11g};Dbq=//oracle.server:1527/database.pdw.prod;Uid=user;Pwd=pswd;")

> con.text <- paste0("Driver={OracleODBC-11g}; ",
         "CONNECTSTRING=(DESCRIPTION=(ADDRESS= (PROTOCOL = TCP)(HOST = oracle.server)(PORT = 1527))(CONNECT_DATA=(SERVICE_NAME = database.pdw.prod))); uid=user;pwd=pswd;")

> con.text <- paste0("Driver=", "OracleODBC-11g"
                     , ";Server=", "oracle.server"
                     , ";Database=", "database.pdw.prod"
                     , ";Uid=", "user"
                     , ";Pwd=", "pwd", ";")

> con.text <- paste0("Driver=", "OracleODBC-11g"
                      , ";Server=", "oracle.server"
                      , ";CONNECTSTRING=" , "(DESCRIPTION=(ADDRESS= (PROTOCOL = TCP)(HOST = oracle.server)(PORT = 1527))(CONNECT_DATA=(SERVICE_NAME = database.pdw.prod)))" 
                      , ";Database=", "database.pdw.prod"
                      , ";Uid=", "user"
                      , ";Pwd=", "pswd", ";")
> con1 <- odbcDriverConnect(connection = con.text)

But for all these strings I am getting following error:

Warning messages:
1: In odbcDriverConnect(connection = con.text) :
 [RODBC] ERROR: state HY000, code 12162, message [unixODBC][Oracle][ODBC][Ora]ORA-12162: TNS:net service name is incorrectly specified
2: In odbcDriverConnect(connection = con.text) : ODBC connection failed

OR

      1: In odbcDriverConnect(connection = con.text) :
  [RODBC] ERROR: state IM002, code 0, message [unixODBC][Driver Manager]Data source name not found, and no default driver specified

Answer 1

The correct sysntaxis you are looking for is

Conex     <- odbcDriverConnect("DRIVER=Oracle en OraClient11g_home2;UID=USERNAME;PWD=PASSWORD;DBQ=//HOSTNAME:PORT/ORACLE_SID;",
             believeNRows = FALSE)

Ex

Conex     <- odbcDriverConnect("DRIVER=Oracle en OraClient11g_home2;UID=John;PWD=Deere;DBQ=//fcoracleserver.youdomain:1521/TestEnvironment;",
             believeNRows = FALSE)

The hard part is to find the name of the Driver, as you can see mine is on spanish.

What I did is I create first a ODBC Conection using the C:\Windows\System32\odbcad32.exe, there you can check the right name of your Oracle or SQL Server driver.

Once you create the conection, you can use odbcDataSources() on R, to see that conection and to find out the driver. Thats really the hard part.

Hope it helps !