LINQ to ApprovalMax Data

Jerod Johnson
Jerod Johnson
Director, Technology Evangelism
LINQ offers versatile querying capabilities within the .NET Framework (v3.0+), offering a straightforward method for programmatic data access through CData ADO.NET Data Providers. In this article, we demonstrate the use of LINQ to retrieve information from the ApprovalMax Data Provider.

This article illustrates using LINQ to access tables within the ApprovalMax via the CData ADO.NET Data Provider for ApprovalMax. To achieve this, we will use LINQ to Entity Framework, which facilitates the generation of connections and can be seamlessly employed with any CData ADO.NET Data Providers to access data through LINQ.

See the help documentation for a guide to setting up an EF 6 project to use the provider.

  1. In a new project in Visual Studio, right-click on the project and choose to add a new item. Add an ADO.NET Entity Data Model.
  2. Choose EF Designer from Database and click Next.
  3. Add a new Data Connection, and change your data source type to "CData ApprovalMax Data Source".
  4. Enter your data source connection information.

    Start by setting the Profile connection property to the location of the ApprovalMax Profile on disk (e.g. C:\profiles\ApprovalMax.apip). Next, set the ProfileSettings connection property to the connection string for ApprovalMax (see below).

    ApprovalMax API Profile Settings

    To authenticate to ApprovalMax and connect to your own data or to allow other users to connect to their data, the ApprovalMax Public API requires the OAuth 2.0 authorization code flow.

    First, you will need to register an OAuth application with ApprovalMax. Sign in to the ApprovalMax Developer Portal (https://developer.approvalmax.com/applications) and create a new application. Your OAuth application will be assigned a Client ID and a Client Secret, and you must register at least one Redirect URI (Callback URL).

    A Premium ApprovalMax subscription (or active trial) is required to use the Public API.

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

    • AuthScheme: Set this to OAuth.
    • InitiateOAuth: Set this to GETANDREFRESH. You can use InitiateOAuth to manage the process to obtain the OAuthAccessToken.
    • OAuthClientId: Set this to the Client ID that is shown in your application settings on the ApprovalMax Developer Portal.
    • OAuthClientSecret: Set this to the Client Secret that is shown in your application settings on the ApprovalMax Developer Portal.
    • CallbackURL: Set this to the Redirect URI that is registered in your application settings.
    • Scope: (Optional) Override the default OAuth scopes. The default value openid offline_access https://www.approvalmax.com/scopes/public_api/read grants read-only access to all tables in this profile and enables refresh tokens. Use the principle of least privilege when narrowing this scope.

    The OAuth Authorization URL is https://identity.approvalmax.com/connect/authorize and the Token URL is https://identity.approvalmax.com/connect/token. Both authorization_code and refresh_token grant types are supported.

    Below is a typical connection string:

    Profile=C:\profiles\ApprovalMax.apip;AuthScheme=OAuth;InitiateOAuth=GETANDREFRESH;OAuthClientId=your_client_id;OAuthClientSecret=your_client_secret;CallbackURL=your_callback_url;
  5. Required connection properties for the data source. (QuickBooks is shown.)
  6. If saving your entity connection to App.Config, set an entity name. In this example we are setting APIEntities as our entity connection in App.Config.
  7. Enter a model name and select any tables or views you would like to include in the model.
The available tables in the underlying data source. (QuickBooks is shown.)

Using the entity you created, you can now perform select commands. For example:


APIEntities context = new APIEntities();

var userprofilesQuery = from userprofiles in context.UserProfiles
  select userprofiles;

foreach (var result in userprofilesQuery) {
  Console.WriteLine("{0} {1} ", result.Id, result.UserId);
}

See "LINQ and Entity Framework" chapter in the help documentation for example queries of the supported LINQ.

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