How to Connect to SAP Ariba Source Data in Using Python: 6 Steps

The rich ecosystem of Python modules lets you get to work quicker and integrate your systems more effectively. With the CData Linux/UNIX ODBC Driver for SAP Ariba Source and the pyodbc module, you can easily build SAP Ariba Source-connected Python applications. This article shows how to use the pyodbc built-in functions to connect to SAP Ariba Source data, execute queries, and output the results.

How to Use the CData ODBC Drivers on UNIX/Linux

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 the help documentation (installed and found online).

1. Install the Driver Manager

Before installing the driver, check 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:

$ sudo apt-get install unixodbc unixodbc-dev

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

$ sudo 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

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

2. Install 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 Red Hat systems and other 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 SAP Ariba Source
...

List the Defined Data Source(s)

$ odbcinst -q -s
CData SAPAribaSource Source
...

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

cdata.odbc.saparibasource.ini

...

[Driver]
DriverManagerEncoding = UTF-16

3. Modify the DSN

The driver installation predefines a system DSN. 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.

In order to connect with SAP Ariba Source, set the following:

• API: Specify which API you would like the provider to retrieve SAP Ariba data from. Select the Supplier, Sourcing Project Management, or Contract API based on your business role (possible values are SupplierDataAPIWithPaginationV4, SourcingProjectManagementAPIV2, or ContractAPIV1).
• DataCenter: The data center where your account's data is hosted.
• Realm: The name of the site you want to access.
• Environment: Indicate whether you are connecting to a test or production environment (possible values are TEST or PRODUCTION).

If you are connecting to the Supplier Data API or the Contract API, additionally set the following:

• User: Id of the user on whose behalf API calls are invoked.
• PasswordAdapter: The password associated with the authenticating User.

If you're connecting to the Supplier API, set ProjectId to the Id of the sourcing project you want to retrieve data from.

Authenticating with OAuth

After setting connection properties, you need to configure OAuth connectivity to authenticate.

• Set AuthScheme to OAuthClient.
• Register an application with the service to obtain the APIKey, OAuthClientId and OAuthClientSecret.

  For more information on creating an OAuth application, refer to the Help documentation.

Automatic OAuth

After setting the following, you are ready to connect:

APIKey: The Application key in your app settings. OAuthClientId: The OAuth Client Id in your app settings. OAuthClientSecret: The OAuth Secret in your app settings.

When you connect, the provider automatically completes the OAuth process:

1. The provider obtains an access token from SAP Ariba and uses it to request data.
2. The provider refreshes the access token automatically when it expires.
3. The OAuth values are saved in memory relative to the location specified in OAuthSettingsLocation.

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

[CData SAPAribaSource Source]
Driver = CData ODBC Driver for SAP Ariba Source
Description = My Description
API = SupplierDataAPIWithPagination-V4
APIKey = wWVLn7WTAXrIRMAzZ6VnuEj7Ekot5jnU
Environment = SANDBOX
Realm = testRealm
AuthScheme = OAuthClient
InitiateOAuth = GETANDREFRESH

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

You can follow the procedure below to install pyodbc and start accessing SAP Ariba Source through Python objects.

4. Install pyodbc

You can use the pip utility to install the module:

pip install pyodbc

Be sure to import with the module with the following:

import pyodbc

5. Connect to SAP Ariba Source Data

You can now connect with an ODBC connection string or a DSN. Below is the syntax for a connection string:

cnxn = pyodbc.connect('DRIVER={CData ODBC Driver for SAP Ariba Source};API=SupplierDataAPIWithPagination-V4;APIKey=wWVLn7WTAXrIRMAzZ6VnuEj7Ekot5jnU;Environment=SANDBOX;Realm=testRealm;AuthScheme=OAuthClient;InitiateOAuth=GETANDREFRESH;')

Below is the syntax for a DSN:

cnxn = pyodbc.connect('DSN=CData SAPAribaSource Sys;')

6. Execute SQL on SAP Ariba Source

Instantiate a Cursor and use the execute method of the Cursor class to execute any SQL statement.

cursor = cnxn.cursor()

Select

You can use fetchall, fetchone, and fetchmany to retrieve Rows returned from SELECT statements:

import pyodbc

cursor = cnxn.cursor()
cnxn = pyodbc.connect('DSN=CData SAPAribaSource Source;User=MyUser;Password=MyPassword')
cursor.execute("SELECT SMVendorID, Category FROM Vendors WHERE Region = 'USA'")
rows = cursor.fetchall()
for row in rows:
 print(row.SMVendorID, row.Category)

You can provide parameterized queries in a sequence or in the argument list:

cursor.execute(
 "SELECT SMVendorID, Category
 FROM Vendors
 WHERE Region = ?", 'USA',1)

Insert

INSERT commands also use the execute method; however, you must subsequently call the commit method after an insert or you will lose your changes:

cursor.execute("INSERT INTO Vendors (Region) VALUES ('USA')")
cnxn.commit()

Update and Delete

As with an insert, you must also call commit after calling execute for an update or delete:

cursor.execute("UPDATE Vendors SET Region = 'USA'")
cnxn.commit()

Metadata Discovery

You can use the getinfo method to retrieve data such as information about the data source and the capabilities of the driver. The getinfo method passes through input to the ODBC SQLGetInfo method.

cnxn.getinfo(pyodbc.SQL_DATA_SOURCE_NAME)

You are now ready to build Python apps in Linux/UNIX environments with connectivity to SAP Ariba Source data, using the CData ODBC Driver for SAP Ariba Source.