chrix75

Connection to Oracle DB

Hi,

I continue my Elixir exploration and now I’m trying to fetch data from our databases that are Oracle DB.
I’ve found I must use the Erlang :odbc module and pass through ODBC connection.

I’ve installed the Oracle ODBC driver and set a Data Source but when I try to connect, that fails.

Below my actions and their results:

iex(18)> :odbc.start()
:ok
iex(19)> {ok, ref} = :odbc.connect('DSN=SIRENE_REC;UID=account;PWD=the_password', [])

13:25:21.953 [error] [79, 68, 66, 67, 58, 32, 114, 101, 99, 101, 105, 118, 101, 100, 32, 117, 110, 101, 120, 112, 101, 99, 116, 101, 100, 32, 105, 110, 102, 111, 58, 32, [123, ['tcp_closed', 44, '#Port<0.1505>'], 125], '\n'] {:error, :connection_closed}

13:25:21.954 [error] GenServer #PID<0.125.0> terminating
** (stop) {:port_exit, :collecting_of_driver_information_faild} Last message: {#Port<0.1503>, {:exit_status, 23}} State: {:state, #Port<0.1503>, {#PID<0.81.0>, #Reference<0.1271860022.1836056577.135740>}, #PID<0.81.0>, :undefined, :on, :undefined, :undefined, :on, :connecting, :undefined, 0, [#Port<0.1501>, #Port<0.1502>], #Port<0.1504>, #Port<0.1505>}

For my noob level, I’m lost

9 comments

#oracle-db

0 4632 9

2019-07-11 18:38:45 UTC

First Post!

NobbZ

Have you done the prechecks from the Erlang ODBC Guide?

In the getting started section there are some things listed to consider and make sure first:

The first thing you need to do, is to make sure you have an ODBC driver installed for the database that you want to access. Both the client machine where you plan to run your erlang node and the server machine running the database needs the the ODBC driver. (In some cases the client and the server may be the same machine).
*Secondly you might need to set environment variables and paths to appropriate values. This may differ a lot between different os’s, databases and ODBC drivers. This is a configuration problem related to the third party product and hence we can not give you a standard solution in this guide.

The Erlang ODBC application consists of both Erlang and C code. The C code is delivered as a precompiled executable for windows, solaris and linux (SLES10) in the commercial build. In the open source distribution it is built the same way as all other application using configure and make. You may want to provide the the path to your ODBC libraries using --with-odbc=PATH.

The payload of the error, which got mangled in some way (perhaps something in the chain has problem with IO-Lists?) says roughly that there was an unexpected {'tcp_closed', '#Port<0.1505>'}. Further I have to assume that this is printed by some erlang subroutine and therefore 'tcp_closed is an atom. Anyway. It boils down to a closed TCP connection, which may have many reasons, but I’ve not used any ODBC so far.

Therefore I want to ask you if you can access to that database from another program that uses ODBC, does this program see the same set of environment variables as your erlang program? Has your version of erlang been compiled with a proper value for --with-odbc?

Post #1

Most Liked

OvermindDL1

Instead of using ODBC (which kind of sucks), have you thought about using a direct Oracle driver like jamdb_oracle or so?

I personally mount my work Oracle database as a FDW inside my PostgreSQL database. ^.^

Post #5

OvermindDL1

All the lower-case j prefixes make me think java. You could always write a Java Erlang node (the java api comes with the erlang distribution) for Elixir to talk to. ^.^

Post #9