Consume BigQuery OData Feeds in PowerBuilder

The CData API Server produces secure feeds of BigQuery data that you can consume in PowerBuilder DataWindows. The API Server supports the major Web services, including OData, Atom, JSON, HTML, CSV, TSV, and RSS. It also supports the major authentication schemes and SSL.

This article shows how to create a DataWindow that uses the CData API Server to execute reads and writes.

Getting Started

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Set Up the API Server

Follow the steps below to begin producing secure BigQuery OData services:

Deploy

The API Server runs on your own server. On Windows, you can deploy using the stand-alone server or IIS. On a Java servlet container, drop in the API Server WAR file. See the help documentation for more information and how-tos.

The API Server is also easy to deploy on Microsoft Azure, Amazon EC2, and Heroku.

Connect to BigQuery

After you deploy the API Server, provide authentication values and other connection properties needed to connect to BigQuery by clicking Settings -> Connections and adding a new connection in the API Server administration console.

Google uses the OAuth authentication standard. To access Google APIs on behalf of individual users, you can use the embedded credentials or you can register your own OAuth app.

OAuth also enables you to use a service account to connect on behalf of users in a Google Apps domain. To authenticate with a service account, register an application to obtain the OAuth JWT values.

In addition to the OAuth values, specify the DatasetId and ProjectId. See the "Getting Started" chapter of the help documentation for a guide to using OAuth.

You can then choose the BigQuery entities you want to allow the API Server access to by clicking Settings -> Resources.

Additionally, click Settings -> Server and change the following settings for compatibility with PowerBuilder:

• Default Format: Select XML (Atom) in the menu.
• Default Version: Select 2.0 in the menu.

Authorize API Server Users

After determining the OData services you want to produce, authorize users by clicking Settings -> Users. The API Server uses authtoken-based authentication and supports the major authentication schemes. Access can also be restricted based on IP address; by default, only connections to the local machine are allowed. You can authenticate as well as encrypt connections with SSL.

Create a Profile for BigQuery

Follow the steps below to use the Database Painter tool to create a database profile for the OData API of the API Server. In the Database Painter, you can graphically manipulate data as well as execute SQL queries.

1. Click Tools -> Database Painter.
2. Right-click the OData node and click New Profile.
3. In the Database Profile Setup dialog, enter the following:
   • Profile Name: Enter a user-friendly name for the profile.
   • URI: Enter the URL to the OData endpoint of the API Server. This URL will resemble the one below:

     http://MyServer:8080/api.rsc

   • Supply User Id and Password: Click this option to use HTTP Basic authentication. Note that the API Server also supports Windows authentication.
   • User Id: Enter the name of an user in the API Server.
   • Password: Enter the authtoken of an user in the API Server.
   👁 The profile for the OData feed. (Salesforce is shown.)
   
4. To view and modify a table, right-click a table and then click Edit Data -> Grid.

👁 Modify database objects in the Database Painter. (Salesforce is shown.)

Using BigQuery Data with PowerBuilder Controls

You can use standard PowerBuilder objects to connect to OData feeds and execute queries. The following example shows how to retrieve BigQuery data into a DataWindow.

You can add the following code to the open method:

SQLCA.DBMS = "ODT"
SQLCA.DBParm = "ConnectString='URI=http://MyServer:8080/api.rsc;UID=MyAPIUser;PWD=MyAuthtoken'";
CONNECT USING SQLCA;
dw_orders.SetTransObject(SQLCA);
dw_orders.Retrieve();