With the CData Cmdlets users can install a data module, set the connection properties, and start scripting. This section provides examples of using our GraphQL 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 GraphQLCmdlets

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

Import-Module GraphQLCmdlets;

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

$conn = Connect-GraphQL -AuthScheme "OAuth" -OAuthVersion "2.0" -CallbackURL "http://localhost:33333" -OauthClientId "MyOAuthClientId" -OAuthClientSecret "MyOAuthClientSecret" -OAuthAccessTokenURL "https://mysite.com/login/oauth/access_token"

Connecting to GraphQL

Set the following to connect:

• URL: Specify the URL of the GraphQL service, for example https://api.example.com/graphql.
• Location: Set this to the file path containing any custom defined schemas for the GraphQL service.

Authenticating to GraphQL

The driver supports the following types of authentication:

• Basic
• OAuth 1.0 & 2.0
• OAuthPKCE
• AWS Cognito Credentials:
  • AwsCognitoSrp
  • AwsCognitoBasic

Basic

Set AuthScheme to Basic. You must specify the User and Password of the GraphQL service.

OAuth

In all OAuth flows, you must set AuthScheme to OAuth and OAuthVersion to 1.0 or 2.0. The following sections assume you have done so.

Desktop Applications

After setting the following connection properties, you are ready to connect:

• OAuthRequestTokenURL: Required for OAuth 1.0. This is the URL where the application makes a request for the request token.
• OAuthAuthorizationURL: Required for OAuth 1.0 and 2.0. This is the URL where the user logs into the service and grants permissions to the application. In OAuth 1.0 if permissions are granted the request token is authorized.
• OAuthAccessTokenURL: Required for OAuth 1.0 and 2.0. This is the URL where the request for the access token is made. In OAuth 1.0 the authorized request token is exchanged for the access token.
• OAuthRefreshTokenURL: Required for OAuth 2.0. In OAuth 2.0 this is the URL where the refresh token is exchanged for a new access token when the old one expires. Note that for your data source this may be the same as the access token URL.
• OAuthClientId: Set this to the client Id in your application settings. This is also called the consumer key.
• OAuthClientSecret: Set this to the client secret in your application settings. This is also called the consumer secret.
• CallbackURL: Set this to http://localhost:33333. If you specified a redirect URL in your application settings, this must match.

When you connect, the cmdlet opens the OAuth endpoint in your default browser. Log in and grant permissions to the application. The cmdlet then completes the OAuth process:

1. Extracts the access token from the callback URL and authenticates requests.
2. Refreshes the access token when it expires.
3. Saves OAuth values. These values persist across connections.

Headless Machines

To create GraphQL data sources on headless servers or other machines on which the cmdlet cannot open a browser, you need to authenticate from another machine. Authentication is a two-step process.

1. Choose one of two options:
   • Option 1: Obtain the OAuthVerifier value as described in "Obtain and Exchange a Verifier Code" below.
   • 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, as described in "Transfer OAuth Settings" below.
2. Then configure the cmdlet to automatically refresh the access token on the headless machine.

Option 1: Obtain and Exchange a Verifier Code

Set the following properties on the headless machine:

• InitiateOAuth: Set this to OFF.
• OAuthClientId: Set this to the application Id in your application settings.
• OAuthClientSecret: Set this to the application secret in your application settings.

You can then follow the steps below to authenticate from another machine and obtain the OAuthVerifier connection property.

1. Call the GetOAuthAuthorizationURL stored procedure with the CallbackURL input parameter set to the exact Redirect URI you specified in your application settings.
2. Save the value of the returned AuthToken and AuthKey if OAuthVersion is set to 1.0. They are used in the next step.
3. Open the returned URL in a browser. Log in and grant permissions to the cmdlet. You are then redirected to the callback URL, which contains the verifier code.
4. Save the value of the verifier code. Later, you must set this in the OAuthVerifier connection property.

On the headless machine, set the following connection properties to obtain the OAuth authentication values:

• OAuthRequestTokenURL: Required for OAuth 1.0. In OAuth 1.0 this is the URL where the application makes a request for the request token.
• OAuthAuthorizationURL: Required for OAuth 1.0 and 2.0. This is the URL where the user logs into the service and grants permissions to the application. In OAuth 1.0 if permissions are granted the request token is authorized.
• OAuthAccessTokenURL: Required for OAuth 1.0 and 2.0. This is the URL where the request for the access token is made. In OAuth 1.0 the authorized request token is exchanged for the access token.
• OAuthRefreshTokenURL: Required for OAuth 2.0. In OAuth 2.0 this is the URL where the refresh token is exchanged for a new access token when the old one expires. Note that for your data source this may be the same as the access token URL.
• OAuthClientId: Set this to the client Id in your application settings.
• OAuthClientSecret: Set this to the client secret in your application settings.
• CallbackURL: Set this to http://localhost:33333. If you specified a redirect URL in your application settings, this must match.

Connect to Data

After the OAuth settings file is generated, set the following properties to connect to data:

• OAuthSettingsLocation: Set this to the location containing the encrypted OAuth authentication values. Make sure this location gives read and write permissions to the provider to enable the automatic refreshing of the access token.
• InitiateOAuth: Set this to REFRESH.

Option 2: Transfer OAuth Settings

Follow the steps below to install the cmdlet on another machine, authenticate, and then transfer the resulting OAuth values.

On a second machine, install the cmdlet and connect with the following properties set:

• OAuthSettingsLocation: Set this to a writable location.
• OAuthClientId: Set this to the Client Id in your application settings.
• OAuthClientSecret: Set this to the Client Secret in your application settings.
• CallbackURL: Set this to the Callback URL in your application settings.

Test the connection to authenticate. The resulting authentication values are written, encrypted, to the location specified by OAuthSettingsLocation. After you have successfully tested the connection, copy the OAuth settings file to your headless machine. On the headless machine, set the following connection properties to connect to data:

• InitiateOAuth: Set this to REFRESH.
• OAuthSettingsLocation: Set this to the location of your OAuth settings file. Make sure this location gives read and write permissions to the cmdlet to enable the automatic refreshing of the access token.

OAuthPKCE

NOTE:OAuth Proof Key for Code Exchange (PKCE) is an extension to the OAuth 2.0 Authorization Code flow.

Desktop Applications

After setting the following, you are ready to connect:

• AuthScheme: Set this to OAuthPKCE.
• InitiateOAuth: Set this to GETANDREFRESH to avoid making the OAuth exchange manually and manually setting the access token in the connection string.
• OAuthClientId: Set this to the client Id generated when creating your OAuth application on the GraphQL service.
• OAuthAuthorizationURL: Set this to the authorization URL for the GraphQL service. This is the URL where the user logs into the service and grants permissions to the OAuth application, for example https://api.example.com/authorize.
• OAuthAccessTokenURL: Set this to the access token URL for the GraphQL service. This is the URL where the request for the access token is made, for example https://api.example.com/token.
• OAuthRefreshTokenURL: Set this to the refresh token URL for the GraphQL service. This is the URL where the refresh token is exchanged for a new access token when the old one expires. Note that for your data source this may be the same as the OAuthAccessTokenURL.

When you connect, the cmdlet opens the OAuth authorization endpoint in your default browser. Log in and grant permissions to the application. The cmdlet then completes the OAuth process:

1. Extracts the authorization code from the callback URL.
2. Exchanges the authorization code for an access and refresh token.
3. Refreshes the access token when it expires.
4. Saves OAuth values. These values persist across connections.

AWS Cognito Credentials

If you want to use the cmdlet with a user registered in a User Pool in AWS Cognito, set the following properties to authenticate:

• AuthScheme: Set this to AwsCognitoSrp (recommended). You can also use AwsCognitoBasic.
• AWSCognitoRegion: Set this to the region of the User Pool.
• AWSUserPoolId: Set this to the User Pool Id.
• AWSUserPoolClientAppId: Set this to the User Pool Client App Id.
• AWSUserPoolClientAppSecret: Set this to the User Pool Client Secret.
• AWSIdentityPoolId: Set this to the Identity Pool Id of the Identity Pool that is linked with the User Pool.
• User: Set this to the username of the user registered in the User Pool.
• Password: Set this to the password of the user registered in the User Pool.

Retrieving Data

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

$results = Select-GraphQL -Connection $conn -Table "Users" -Columns @("Name, Email") -Where "UserLogin='mojombo'"

The Invoke-GraphQL 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-GraphQL -Connection $conn -Table Users -Where "UserLogin = 'mojombo'" | Select -Property * -ExcludeProperty Connection,Table,Columns | Export-Csv -Path c:\myUsersData.csv -NoTypeInformation

You will notice that we piped the results from Select-GraphQL 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-GraphQL -AuthScheme "OAuth" -OAuthVersion "2.0" -CallbackURL "http://localhost:33333" -OauthClientId "MyOAuthClientId" -OAuthClientSecret "MyOAuthClientSecret" -OAuthAccessTokenURL "https://mysite.com/login/oauth/access_token"
PS C:\> $row = Select-GraphQL -Connection $conn -Table "Users" -Columns (Name, Email) -Where "UserLogin = 'mojombo'" | select -first 1
PS C:\> $row | ConvertTo-Json
{
  "Connection":  {

  },
  "Table":  "Users",
  "Columns":  [

  ],
  "Name":  "MyName",
  "Email":  "MyEmail"
}