Write a Simple Go Application to work with Oracle Eloqua Reporting Data on Linux

Go is an open source programming language that enables you to easily build software on Linux/UNIX machines. When Go is paired with the ODBC Driver for Oracle Eloqua Reporting and unixODBC you are able write applications with connectivity to live Oracle Eloqua Reporting data. This article will walk you through the process of installing the ODBC Driver for Oracle Eloqua Reporting, configuring a connection using the unixODBC Driver Manager, and creating a simple Go application to work with Oracle Eloqua Reporting data.

Using the CData ODBC Drivers on a Unix/Linux Machine

The CData ODBC Drivers are supported in various Red Hat-based and Debian-based systems, including Ubuntu, Debian, RHEL, CentOS, and Fedora. There are also several libraries and packages that are required, many of which may be installed by default, depending on your system. For more information on the supported versions of Linux operating systems and the required libraries, please refer to the "Getting Started" section in help documentation (installed and found online).

Installing the Driver Manager

Before installing the driver, you need to be sure that your system has a driver manager. For this article, you will use unixODBC, a free and open source ODBC driver manager that is widely supported.

For Debian-based systems like Ubuntu, you can install unixODBC with the APT package manager:

apt-get install unixodbc unixodbc-dev

For systems based on Red Hat Linux, you can install unixODBC with yum or dnf:

yum install unixODBC unixODBC-devel

The unixODBC driver manager reads information about drivers from an odbcinst.ini file and about data sources from an odbc.ini file. You can determine the location of the configuration files on your system by entering the following command into a terminal:

odbcinst -j

NOTE: You may need to install odbcinst. Use the following command in a terminal:

apt install odbcinst

The output of the command will display the locations of the configuration files for ODBC data sources and registered ODBC drivers. User data sources can only be accessed by the user account whose home folder the odbc.ini is located in. System data sources can be accessed by all users. Below is an example of the output of this command:

DRIVERS............: /etc/odbcinst.ini
SYSTEM DATA SOURCES: /etc/odbc.ini
FILE DATA SOURCES..: /etc/ODBCDataSources
USER DATA SOURCES..: /home/myuser/.odbc.ini
SQLULEN Size.......: 8
SQLLEN Size........: 8
SQLSETPOSIROW Size.: 8

Installing the Driver

You can download the driver in standard package formats: the Debian .deb package format or the .rpm file format. Once you have downloaded the file, you can install the driver from the terminal.

The driver installer registers the driver with unixODBC and creates a system DSN, which can be used later in any tools or applications that support ODBC connectivity.

For Debian-based systems like Ubuntu, run the following command with sudo or as root:

dpkg -i /path/to/package.deb

For systems that support .rpms, run the following command with sudo or as root:

rpm -i /path/to/package.rpm

Once the driver is installed, you can list the registered drivers and defined data sources using the unixODBC driver manager:

List the Registered Driver(s)

odbcinst -q -d
CData ODBC Driver for Oracle Eloqua Reporting
...

List the Defined Data Source(s)

odbcinst -q -s
CData OracleEloquaReporting Source
...

To use the CData ODBC Driver for Oracle Eloqua Reporting with unixODBC, you need to ensure that the driver is configured to use UTF-16. To do so, edit the INI file for the driver (cdata.odbc.oracleeloquareporting.ini), which can be found in the lib folder in the installation location (typically /opt/cdata/cdata-odbc-driver-for-oracleeloquareporting), as follows:

cdata.odbc.oracleeloquareporting.ini

...

[Driver]
DriverManagerEncoding = UTF-16

Modifying the DSN

When the driver is installed, a system DSN should be predefined. You can modify the DSN by editing the system data sources file (/etc/odbc.ini) and defining the required connection properties. Additionally, you can create user-specific DSNs that will not require root access to modify in $HOME/.odbc.ini.

Oracle Eloqua Reporting supports the following authentication methods:

• Basic authentication (User and Password)
• OAuth 2.0 code grant flow
• OAuth 2.0 password grant flow

Basic Authentication (User and Password)

To perform authentication with a user and password, specify these properties:

• AuthScheme: Basic.
• Company: The company name associated with your Oracle Eloqua Reporting account.
• User: Your login account name.
• Password: Your login password.

OAuth Authentication (Code Grant Flow)

To authenticate with the OAuth code grant flow, you must set AuthScheme to OAuth and create a custom OAuth application. For information about how to create a custom OAuth application, see the Help documentation.

Then set the following properties:

• InitiateOAuth: GETANDREFRESH. Used to automatically get and refresh the OAuthAccessToken.
• OAuthClientId: The client Id assigned when you registered your application.
• OAuthClientSecret: The client secret that was assigned when you registered your application.
• CallbackURL: The redirect URI that was defined when you registered your application.

When you connect, the driver opens Oracle Eloqua Reporting's OAuth endpoint in your default browser. Log in and grant permissions to the application. When the access token expires, the driver refreshes it automatically.

OAuth Authentication (Password Grant Flow)

With the OAuth password grant flow, you can use your OAuth application's credentials alongside your user credentials to authenticate without the need to grant permission manually via a browser prompt. You must create an OAuth app (see the Help documentation) to use this authentication method.

Set the following properties:

• AuthScheme: OAuthPassword
• Company: The company's unique identifier.
• User: Your login account name.
• Password: Your login password.
• OAuthClientId: The client Id assigned when you registered your custom OAuth application.
• OAuthClientSecret: The client secret assigned when you registered your custom OAuth application.

/etc/odbc.ini or $HOME/.odbc.ini

[CData OracleEloquaReporting Source]
Driver = /opt/cdata/cdata-odbc-driver-for-oracleeloquareporting/lib/liboracleeloquareportingodbc.x64.so
Description = My Description
AuthScheme = Basic
User = user
Password = password
Company = MyCompany

For specific information on using these configuration files, please refer to the help documentation (installed and found online).

Creating a Simple Go App for Oracle Eloqua Reporting Data

With the Driver Manager installed and the DSN configured, you are ready to create a simple Go application to work with your Oracle Eloqua Reporting data. To start, install a Go driver for ODBC databases. While there are several options available, this article will use the odbc driver found at https://github.com/alexbrainman/odbc.

Installing ODBC on Linux

There are a series of steps required to install the ODBC driver for Go.

1. Create the $HOME/golang/go path (if it does not exist) by entering the following commands in a terminal:

   mkdir /root/golang
   mkdir /root/golang/go
       

2. Define the GOPATH environment variable:

   export GOPATH=$HOME/golang/go
     

3. Create a module inside the new Go directory:

   cd $GOPATH
   go mod init myproject
       

4. Install the Go driver for ODBC databases:

   go get http://github.com/alexbrainman/odbc
     

Now you are ready to create and execute a simple Go application.

Sample Go Application

The sample application issues a simple SQL SELECT query for Oracle Eloqua Reporting data and displays the results. Create the directory $GOPATH/src/cdata-odbc-eloquareporting and create a new Go source file, copying the source code from below.

cdata-odbc-eloquareporting.go

package main

import (
  _ "github.com/alexbrainman/odbc"
  "database/sql"
  "log"
  "fmt"
)

func main() {
  db, err := sql.Open("odbc",
    "DSN=CData OracleEloquaReporting Source")
  if err != nil {
    log.Fatal(err)
  }

  var (
     string
     string
  )

  rows, err := db.Query("SELECT ,  FROM  WHERE  = ?", "")
  if err != nil {
    log.Fatal(err)
  }
  defer rows.Close()
  for rows.Next() {
    err := rows.Scan(&, &)
    if err != nil {
      log.Fatal(err)
    }
    fmt.Println(, )
  }
  err = rows.Err()
  if err != nil {
    log.Fatal(err)
  }

  defer db.Close()
}

In the terminal, navigate to the Go application directory and build the application:

go build

After the application builds, you will be able to execute the application, displaying your Oracle Eloqua Reporting data:

./cdata-odbc-eloquareporting

At this point, you have a simple Go application for working with Oracle Eloqua Reporting data. From here, you can easily expand the application, adding deeper read functionality through familiar SQL queries.