Cmdlets for OData

Build 23.0.8839

Establishing a Connection

With the CData Cmdlets users can install a data module, set the connection properties, and start scripting. This section provides examples of using our OData Cmdlets with native PowerShell cmdlets, like the CSV import and export cmdlets.

Installing and Connecting

If you have PSGet, installing the cmdlets can be accomplished from the PowerShell Gallery with the following command. You can also obtain a setup from the CData site. 

Install-Module ODataCmdlets

The following line is then added to your profile, loading the cmdlets on the next session: 

Import-Module ODataCmdlets;

You can then use the Connect-OData cmdlet to create a connection object that can be passed to other cmdlets: 

$conn = Connect-OData -User 'MyUser' -Password 'MyPassword' -URL 'http://myserver/myOrgRoot'

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.

You can also specify a CacheLocation to store the metadata of your OData organization. This keeps the CData Cmdlets PowerShell Module for OData from having to send requests for metadata on each connection.

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

When the access token expires, the cmdlet refreshes it automatically.

Automatic refresh of the OAuth access token:

To have the cmdlet automatically refresh the OAuth access token:

  1. 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 cmdlet to save the OAuth values, which persist across connections.
  2. 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.

  1. To manually refresh the OAuthAccessToken after the ExpiresIn period (returned by GetOAuthAccessToken) has elapsed, call the RefreshOAuthAccessToken stored procedure.
  2. Set these connection properties:

    • OAuthClientId: The Client Id in your custom OAuth application settings.
    • OAuthClientSecret: The Client Secret in your custom OAuth application settings.

  3. Call RefreshOAuthAccessToken with OAuthRefreshToken set to the OAuth refresh token returned by GetOAuthAccessToken.
  4. 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.

Headless Machines

If you need to log in to a resource that resides on a headless machine, you must authenticate on another device that has an internet browser. You can do this in either of the following ways:

  • Option 1: Obtain the OAuthVerifier value.
  • Option 2: Install the cmdlet on a machine with an internet browser and transfer the OAuth authentication values after you authenticate through the usual browser-based flow.

After you execute either Option 1 or Option 2, configure the driver to automatically refresh the access token on the headless machine.

Option 1: Obtaining and Exchanging a Verifier Code

To obtain a verifier code, you must authenticate at the OAuth authorization URL as follows:

  1. Authenticate from the machine with an internet browser, and obtain the OAuthVerifier connection property.

    Set these properties:

    • InitiateOAuth: OFF.
    • OAuthClientId: The client Id assigned when you registered your application.
    • OAuthClientSecret: The client secret assigned when you registered your application.

  2. Call the GetOAuthAuthorizationUrl stored procedure. The stored procedure returns the CallbackURL established when the custom OAuth application was registered. (See Creating a Custom OAuth Application.)

    Copy this URL and paste it into a new browser tab.

  3. Log in and grant permissions to the cmdlet. The OAuth application redirects you the redirect URI, with a parameter called code appended. Note the value of this parameter; you will need it later, to configure the OAuthVerifier connection property.

  4. Exchange the OAuth verifier code for OAuth refresh and access tokens. On the headless machine, to obtain the OAuth authentication values, set these properties:

    • InitiateOAuth: REFRESH.
    • OAuthVerifier: The noted verifier code (the value of the code parameter in the redirect URI).
    • OAuthSettingsLocation: Persist the encrypted OAuth authentication values to the specified file.
    • OAuthClientId: The client Id in your custom OAuth application settings.
    • OAuthClientSecret: The client secret in the custom OAuth application settings.

  5. Test the connection to generate the OAuth settings file.

  6. You are ready to connect after you re-set these properties:

    • InitiateOAuth: REFRESH.
    • OAuthSettingsLocation: The file containing the encrypted OAuth authentication values. To enable the automatic refreshing of the access token, be sure that this file gives read and write permissions to the cmdlet.
    • OAuthClientId: The client Id assigned when you registered your application.
    • OAuthClientSecret: The client secret assigned when you registered your application.

Option 2: Transferring OAuth Settings

Prior to connecting on a headless machine, you must install and create a connection with the driver on a device that supports an internet browser. Set the connection properties as described above in "Desktop Applications".

After completing the instructions in "Desktop Applications", the resulting authentication values are encrypted and written to the path specified by OAuthSettingsLocation. The default filename is OAuthSettings.txt.

Test the connection to generate the OAuth settings file, then copy the OAuth settings file to your headless machine.

To connect to data via the headless machine, set these connection properties:

  • InitiateOAuth: REFRESH
  • OAuthSettingsLocation: The path to the OAuth settings file you copied from the machine with the browser. To enable automatic refreshing of the access token, ensure that this file gives read and write permissions to the cmdlet.
  • OAuthClientId: The client Id assigned when you registered your custom OAuth application.
  • OAuthClientSecret: The client secret assigned when you registered your custom OAuth application.

Azure AD

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

The CData Cmdlets PowerShell Module 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 cmdlet 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.

Retrieving Data

The Select-OData cmdlet provides a native PowerShell interface for retrieving data: 

$results = Select-OData -Connection $conn -Table "Lead" -Columns @("Id, FullName") -Where "FirstName='Bartholomew'"
The Invoke-OData cmdlet provides an SQL interface. This cmdlet can be used to execute an SQL query via the Query parameter.

Piping Cmdlet Output

The cmdlets return row objects to the pipeline one row at a time. The following line exports results to a CSV file: 

Select-OData -Connection $conn -Table Lead -Where "FirstName <> 'Bartholomew'" | Select -Property * -ExcludeProperty Connection,Table,Columns | Export-Csv -Path c:\myLeadData.csv -NoTypeInformation

You will notice that we piped the results from Select-OData into a Select-Object cmdlet and excluded some properties before piping them into an Export-CSV cmdlet. We do this because the CData Cmdlets append Connection, Table, and Columns information onto each row object in the result set, and we do not necessarily want that information in our CSV file.

However, this makes it easy to pipe the output of one cmdlet to another. The following is an example of converting a result set to JSON: 

 
PS C:\> $conn  = Connect-OData -User 'MyUser' -Password 'MyPassword' -URL 'http://myserver/myOrgRoot'
PS C:\> $row = Select-OData -Connection $conn -Table "Lead" -Columns (Id, FullName) -Where "FirstName <> 'Bartholomew'" | select -first 1
PS C:\> $row | ConvertTo-Json
{
  "Connection":  {

  },
  "Table":  "Lead",
  "Columns":  [

  ],
  "Id":  "MyId",
  "FullName":  "MyFullName"
}

Deleting Data

The following line deletes any records that match the criteria: 

Select-OData -Connection $conn -Table Lead -Where "FirstName = 'Bartholomew'" | Remove-OData

Modifying Data

The cmdlets make data transformation easy as well as data cleansing. The following example loads data from a CSV file into OData, checking first whether a record already exists and needs to be updated instead of inserted. 

Import-Csv -Path C:\MyLeadUpdates.csv | %{
  $record = Select-OData -Connection $conn -Table Lead -Where ("Id = `'"+$_.Id+"`'")
  if($record){
    Update-OData -Connection $conn -Table Lead -Columns @("Id","FullName") -Values @($_.Id, $_.FullName) -Where "Id  = `'$_.Id`'"
  }else{
    Add-OData -Connection $conn -Table Lead -Columns @("Id","FullName") -Values @($_.Id, $_.FullName)
  }
}

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Build 23.0.8839