Establishing a Connection

Configure a Connection Profile

From the CData ribbon, click Get Data and select From OData connection/s to launch the CData Query window. To setup a new connection, you will have to click the New OData Connection button. Here you can set the connection settings, test the connection, and save the connection profile.

Connecting to OData

To connect to OData, you must set the Url to a valid OData service root URI. If your OData service does not have a root document, have FeedURL point to the specific entity you want to expose as a table.

Authenticating to OData

OData supports authentication via:

HTTP
Kerberos
SharePoint Online
OAuth (Azure AD)

HTTP Auth Schemes

For authenticating via HTTP, set AuthScheme according to the following table.


Scheme	AuthScheme	Other Settings
None	None	Use if no authentication is desired.
Basic	Basic	User, Password
NTLM (1)	NTLM	User, Password
Digest (if supported)	Digest	User, Password

(1) NTLM is a type of Windows authentication often used across a LAN using your Windows user credentials. Set the User and Password if you are not connecting from a Windows machine, or if your currently logged in user account should not be used for the connection.

Kerberos

To authenticate to OData using Kerberos, set these properties:

hive.server2.authentication: Kerberos.
AuthScheme: NEGOTIATE.
KerberosKDC: The host name or IP Address of your Kerberos KDC machine.
KerberosSPN: The service and host of the OData Kerberos Principal. Find this value just before the '@' symbol of the principal value.

SharePoint Online

SharePoint Online connections are established by retrieving a SharePoint Online cookie. To authenticate, set these properties:

AuthScheme: SharePointOnline.
User: Your SharePoint Online user account.
Password: Your SharePoint Online password.

OAuth

To enable this authentication from all OAuth flows in OData, you must create a custom OAuth application, and set AuthScheme to OAuth.

The following subsections describe how to authenticate to OData from three common authentication flows. For information about how to create a custom OAuth application, see Creating a Custom OAuth Application. For a complete list of connection string properties available in OData, see Connection.

Desktop Applications

To authenticate with the credentials for a custom OAuth application, you must get and refresh the OAuth access token. After you do that, you are ready to connect.

Get and refresh the OAuth access token:

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 add-in opens OData's OAuth endpoint in your default browser. Log in and grant permissions to the application.

When the access token expires, the add-in refreshes it automatically.

Automatic refresh of the OAuth access token:

To have the add-in automatically refresh the OAuth access token:

Before connecting to data for the first time, set these connection parameters:
- InitiateOAuth: REFRESH.
- OAuthClientId: The client Id in your custom OAuth application settings.
- OAuthClientSecret: The client secret in your custom OAuth application settings.
- OAuthAccessToken: The access token returned by GetOAuthAccessToken.
- OAuthSettingsLocation: The path where you want the add-in to save the OAuth values, which persist across connections.
On subsequent data connections, set:
- InitiateOAuth
- OAuthSettingsLocation

Manual refresh of the OAuth access token:

The only value needed to manually refresh the OAuth access token is the OAuth refresh token.

To manually refresh the OAuthAccessToken after the ExpiresIn period (returned by GetOAuthAccessToken) has elapsed, call the RefreshOAuthAccessToken stored procedure.
Set these connection properties:
- OAuthClientId: The Client Id in your custom OAuth application settings.
- OAuthClientSecret: The Client Secret in your custom OAuth application settings.
Call RefreshOAuthAccessToken with OAuthRefreshToken set to the OAuth refresh token returned by GetOAuthAccessToken.
After the new tokens have been retrieved, set the OAuthAccessToken property to the value returned by RefreshOAuthAccessToken. This opens a new connection.

Store the OAuth refresh token so that you can use it to manually refresh the OAuth access token after it has expired.

Azure AD

Azure AD supports a form of OAuth that goes through Azure. Set the AuthScheme to AzureAD.

The CData Excel Add-In for OData automatically takes care of known Azure URLs internally, so it is not necessary to specify any of the usual OAuth connection properties, such as OAuthAccessTokenURL, OAuthAuthorizationURL, OAuthRefreshTokenURL, and OAuthRequestTokenURL.

Other connection properties may be required for this connection method, including:

Scope: Must be specified if InitiateOAuth is set to GETANDREFRESH as the Scope is submitted to Microsoft during retrieval of credentails. This varies depending on the service, but is generally a combination of the resource (hostname in the URL) and permission name. For example: https://host/user_impersonation.
AzureADResource: The specific Azure Resource to authenticate against during Microsoft login. If none is specified, your user account's default resource is used.
AzureADTenant: The specific Azure Tenant to authenticate against during Microsoft login. If none is specified, your user account's default tenant via the common login endpoint is used. This may not be correct, depending on the specific resource you are connecting to, or if the resource is stored on a seperate tenant.

Otherwise, the steps to authenticate are identical to the descriptions of Desktop, Web, and Headless Machine authentication, above.

For information about how to create a custom OAuth application for use with Azure AD, see Creating a Custom OAuth Application.

Securing OData Connections

By default, the add-in attempts to negotiate SSL/TLS by checking the server's certificate against the system's trusted certificate store. To specify another certificate, see the SSLServerCert property for the available formats to do so.

Connection Properties

The Connection properties describe the various options that can be used to establish a connection.

Managing Connections

After successfully authenticating to OData you will be able to customize the data you are importing. To learn more about this, see Managing Connections.

Excel Add-In for OData