Linux DSN Configuration

This section describes how to set up ODBC connectivity and configure DSNs on several Linux distributions: Debian-based systems, like Ubuntu, and Red Hat Linux platforms, like Red Hat Enterprise Linux (RHEL) and Fedora.

Minimum Linux Versions

Here are the minimum supported versions for Red Hat-based and Debian-based systems:


OS	Min. Version
Ubuntu	18.04
Debian	10
RHEL	8
Fedora	28
SUSE	15

Installing the Driver Dependencies

Run the following commands as root or with sudo to install the necessary dependencies:

Debian/Ubuntu:

apt-get install libc6 libstdc++6 zlib1g libgcc1

RHEL/Fedora:
```
yum install glibc libstdc++ zlib libgcc
```

Installing the Driver

You can use standard package management systems to install the driver.

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

dpkg -i /path/to/driver/setup/ExcelOnlineODBCDriverforUnix.deb

On systems that support the RPM package format, run the following command with root or sudo:

rpm -ivh /path/to/driver/ExcelOnlineODBCDriverforUnix.rpm

Licensing the Driver

Run the following commands to license the driver. To activate a trial, omit the <key> input.

cd /opt/cdata/cdata-odbc-driver-for-excelonline/bin/
sudo ./install-license.sh <key>

Connecting through the Driver Manager

The driver manager loads the driver and passes function calls from the application to the driver. You need to register the driver with the driver manager and you define DSNs in the driver manager's configuration files.

The driver installation registers the driver with the unixODBC driver manager and creates a system DSN. The unixODBC driver manager can be used from Python and from many other applications. Your application may embed another driver manager.

Creating the DSN

See Using unixODBC to install unixODBC and configure DSNs. See Using the DataDirect Driver Manager to create a DSN to connect to OBIEE, Informatica, and SAS.

Connecting to Microsoft Excel Online

There are two authentication methods available for connecting to Microsoft Excel Online data source:

OAuth 2.0-based methods: Microsoft Excel Online provides OAuth 2.0-based authentication via both Azure AD and Azure Service Principal.
- For Azure AD authentication, set AuthScheme to AzureAD.
- For Azure Service Principal authentication, set AuthScheme to AzureServicePrincipal.
Managed Service Identity (MSI) authentication. To use this method, set AuthScheme to AzureMSI.

Azure AD

Azure AD is user-based authentication. Credentials are supplied to connect AzureAD to Microsoft Excel Online via a Desktop application. To use the embedded credentials for authentication, leave the OAuth credentials (OAuthClientId and OAuthClientSecret) blank.

For connecting via a Web application, you must create a custom OAuth Azure AD application. The creation of a Custom Azure AD application establishes the OAuth credentials OAuthClientId and OAuthClientSecret. For a discussion of how to create a custom Azure AD application, and reasons why that might be advantageous even if you are not connecting via a Web application, see Creating an Azure AD Application.

Azure Service Principal

The authentication as an Azure Service Principal is handled via the OAuth Client Credentials flow. It does not involve direct user authentication. Instead, credentials are created for just the application itself. All tasks taken by the app are done without a default user context, but based on the assigned roles. The application access to the resources is controlled through the assigned roles' permissions.

Create an AzureAD App and an Azure Service Principal

When authenticating using an Azure Service Principal, you must create and register an Azure AD application with an Azure AD tenant. See Creating an Azure AD Application for more details.

In your App Registration in portal.azure.com, navigate to API Permissions and select the Microsoft Graph permissions. There are two distinct sets of permissions: Delegated permissions and Application permissions. The permissions used during client credential authentication are under Application Permissions.

Assign a role to the application

To access resources in your subscription, you must assign a role to the application.

Open the Subscriptions page by searching and selecting the Subscriptions service from the search bar.
Select the subscription to assign the application to.
Open the Access control (IAM) and select Add > Add role assignment to open the Add role assignment page.
Select Owner as the role to assign to your created Azure AD app.

Complete the Authentication Choose whether to use a client secret or a certificate and follow the relevant steps below.

Client Secret

Set these connection properties:

AuthScheme: AzureServicePrincipal to use a client secret.
InitiateOAuth: GETANDREFRESH. You can use InitiateOAuth to avoid repeating the OAuth exchange and manually setting the OAuthAccessToken.
AzureTenant: The tenant you want to connect to.
OAuthClientId: The client Id in your application settings.
OAuthClientSecret: The client secret in your application settings.

Certificate

Set these connection properties:

AuthScheme: AzureServicePrincipalCert to use a certificate.
InitiateOAuth: GETANDREFRESH. You can use InitiateOAuth to avoid repeating the OAuth exchange and manually setting the OAuthAccessToken.
AzureTenant: The tenant you want to connect to.
OAuthJWTCert: The JWT Certificate store.
OAuthJWTCertType: The type of the certificate store specified by OAuthJWTCert.

You are now ready to connect. Authentication with client credentials takes place automatically like any other connection, except there is no window opened prompting the user. Because there is no user context, there is no need for a browser popup. Connections take place and are handled internally.

Managed Service Identity (MSI)

If you are running Microsoft Excel Online on an Azure VM and want to leverage MSI to connect, set AuthScheme to AzureMSI.

User-Managed Identities

To obtain a token for a managed identity, use the OAuthClientId property to specify the managed identity's "client_id".

When your VM has multiple user-assigned managed identities, you must also specify OAuthClientId.

Connecting to a Workbook

The driver exposes workbooks and worksheets from drives you specify in your Microsoft account. You can connect to a workbook by providing authentication to Excel Online and setting any of the following properties.

To control which drives are discovered:

Drive: The ID of a specific drive. You can use the Drives and SharePointSites views to view all the sites and drives you have access to.
SharepointURL: The browser URL of a SharePoint site. The driver will expose all drives under the site.
OAuthClientId: If AuthScheme is set to AzureServicePrincipal or if OAuthGrantType is set to CLIENT, the drive associated with your OAuth app will be exposed.

If none of the above are specified, access is restricted to the authenticated user's personal drive.

To control which workbooks and worksheets are exposed OR which drives are exposed:

Workbook: The name or Id of the workbook. An authenticate user can view a list of information about the available workbooks by executing a query to the Workbooks view.
UseSandbox: True to connect to a workbook in a sandbox account; otherwise, leave blank.
BrowsableSchemas: A list of drive names to expose.
Tables: A list of table names to expose.

Executing SQL Against Worksheet Data

For information on how to execute data manipulation SQL against worksheets and ranges, see:

For details on how the driver models worksheets and cells as tables and columns, See Data Model.

Retrieving Data from SharePoint Excel Files

To retrieve data from Sharepoint Excel files, set the SharepointURL connection property to the URL of your Sharepoint site. For example,

 SharepointURL=https://mysite.sharepoint.com/

The driver automatically looks up each document library you have in SharePoint and lists it as a schema. Individual Excel workbooks and worksheets are listed as tables in the format Workbook_Worksheet under their corresponding document library. This works in the same manner as listing your own personal Excel documents when SharepointURL is not set.

Refreshing OAuth Values

The driver can refresh the temporary OAuth access tokens obtained during the browser-based OAuth authentication exchange. By default, the driver saves the encrypted tokens in the odbc.ini file corresponding to the DSN. Access to this odbc.ini file can be restricted in the case of System DSNs.

To enable the automatic token exchange, you can give the driver write access to the system odbc.ini. Or, you can set the OAuthSettingsLocation connection property to an alternate file path, to which the driver would have read and write access.

    OAuthSettingsLocation=/tmp/oauthsettings.txt

Installing Dependencies for OAuth Authentication

The OAuth authentication standard requires the authenticating user to interact with Microsoft Excel Online, using a web-browser. If the first OAuth interaction is to be done on the same machine the driver is installed on, for example, a desktop application, the driver needs access to the xdg-open program, which opens the default browser.

To satisfy this dependency, install the corresponding package with your package manager:


Debian/Ubuntu Package	RHEL/Fedora Package	File
xdg-utils	xdg-utils	xdg-open

Set the Driver Encoding

The ODBC drivers need to specify which encoding to use with the ODBC Driver Manager. By default, the CData ODBC Drivers for Unix are configured to use UTF-16 which is compatible with unixODBC, but other Driver Managers may require alternative encoding.

Alternatively, if you are using the ODBC driver from an application that uses the ANSI ODBC API it may be necessary to set the ANSI code page. For example, to import Japanese characters in an ANSI application, you can specify the code page in the config file '/opt/cdata/cdata-odbc-driver-for-excelonline/lib/cdata.odbc.excelonline.ini':

[Driver]
AnsiCodePage = 932

ODBC Driver for Microsoft Excel Online