Consume Presto OData Feeds in PowerBuilder



This article demonstrates how to consume Presto data as OData feeds from PowerBuilder using the API Server.

The CData API Server, when paired with the ADO.NET Provider for Presto (or any of 200+ other ADO.NET Providers), produces secure feeds of Presto 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.

About Presto Data Integration

Accessing and integrating live data from Trino and Presto SQL engines has never been easier with CData. Customers rely on CData connectivity to:

  • Access data from Trino v345 and above (formerly PrestoSQL) and Presto v0.242 and above (formerly PrestoDB)
  • Read and write access all of the data underlying your Trino or Presto instances
  • Optimized query generation for maximum throughput.

Presto and Trino allow users to access a variety of underlying data sources through a single endpoint. When paired with CData connectivity, users get pure, SQL-92 access to their instances, allowing them to integrate business data with a data warehouse or easily access live data directly from their preferred tools, like Power BI and Tableau.

In many cases, CData's live connectivity surpasses the native import functionality available in tools. One customer was unable to effectively use Power BI due to the size of the datasets needed for reporting. When the company implemented the CData Power BI Connector for Presto they were able to generate reports in real-time using the DirectQuery connection mode.


Getting Started


Set Up the API Server

Follow the steps below to begin producing secure Presto 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 Presto

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

Set the Server and Port connection properties to connect, in addition to any authentication properties that may be required.

To enable TLS/SSL, set UseSSL to true.

Authenticating with LDAP

In order to authenticate with LDAP, set the following connection properties:

  • AuthScheme: Set this to LDAP.
  • User: The username being authenticated with in LDAP.
  • Password: The password associated with the User you are authenticating against LDAP with.

Authenticating with Kerberos

In order to authenticate with KERBEROS, set the following connection properties:

  • AuthScheme: Set this to KERBEROS.
  • KerberosKDC: The Kerberos Key Distribution Center (KDC) service used to authenticate the user.
  • KerberosRealm: The Kerberos Realm used to authenticate the user with.
  • KerberosSPN: The Service Principal Name for the Kerberos Domain Controller.
  • KerberosKeytabFile: The Keytab file containing your pairs of Kerberos principals and encrypted keys.
  • User: The user who is authenticating to Kerberos.
  • Password: The password used to authenticate to Kerberos.

You can then choose the Presto 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 Presto

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:8032/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.
  4. To view and modify a table, right-click a table and then click Edit Data -> Grid.

Using Presto 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 Presto data into a DataWindow.

You can add the following code to the open method:

SQLCA.DBMS = "ODT" SQLCA.DBParm = "ConnectString='URI=http://MyServer:8032/api.rsc;UID=MyAPIUser;PWD=MyAuthtoken'"; CONNECT USING SQLCA; dw_customer.SetTransObject(SQLCA); dw_customer.Retrieve();

Ready to get started?

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CData API Server