How to connect PolyBase to Cvent

PolyBase for SQL Server allows you to query external data by using the same Transact-SQL syntax used to query a database table. When paired with the CData ODBC Driver for Cvent, you get access to your Cvent data directly alongside your SQL Server data. This article describes creating an external data source and external tables to grant access to live Cvent data using T-SQL queries.

NOTE: PolyBase is only available on SQL Server 19 and above, and only for Standard SQL Server.

The CData ODBC drivers offer unmatched performance for interacting with live Cvent data using PolyBase due to optimized data processing built into the driver. When you issue complex SQL queries from SQL Server to Cvent, the driver pushes down supported SQL operations, like filters and aggregations, directly to Cvent and utilizes the embedded SQL engine to process unsupported operations (often SQL functions and JOIN operations) client-side. And with PolyBase, you can also join SQL Server data with Cvent data, using a single query to pull data from distributed sources.

Connect to Cvent

If you have not already, first specify connection properties in an ODBC DSN (data source name). This is the last step of the driver installation. You can use the Microsoft ODBC Data Source Administrator to create and configure ODBC DSNs. To create an external data source in SQL Server using PolyBase, configure a System DSN (CData Cvent Sys is created automatically).

Before you can authenticate to Cvent, you must create a workspace and an OAuth application.

Creating a Workspace

To create a workspace:

1. Sign into Cvent and navigate to App Switcher (the blue button in the upper right corner of the page) >> Admin.
2. In the Admin menu, navigate to Integrations >> REST API.
3. A new tab launches for Developer Management. Click on Manage API Access in the new tab.
4. Create a Workspace and name it. Select the scopes you would like your developers to have access to. Scopes control what data domains the developer can access.
   • Choose All to allow developers to choose any scope, and any future scopes added to the REST API.
   • Choose Custom to limit the scopes developers can choose for their OAuth apps to selected scopes. To access all tables exposed by the driver, you need to set the following scopes:

     event/attendees:read	event/attendees:write	event/contacts:read
     event/contacts:write	event/custom-fields:read	event/custom-fields:write
     event/events:read	event/events:write	event/sessions:delete
     event/sessions:read	event/sessions:write	event/speakers:delete
     event/speakers:read	event/speakers:write	budget/budget-items:read
     budget/budget-items:write	exhibitor/exhibitors:read	exhibitor/exhibitors:write
     survey/surveys:read	survey/surveys:write

Creating an OAuth Application

After you have set up a Workspace and invited them, developers can sign up and create a custom OAuth app. See the Creating a Custom OAuth Application section in the Help documentation for more information.

Connecting to Cvent

After creating an OAuth application, set the following connection properties to connect to Cvent:

• InitiateOAuth: GETANDREFRESH. Used to automatically get and refresh the OAuthAccessToken.
• OAuthClientId: The Client ID associated with the OAuth application. You can find this on the Applications page in the Cvent Developer Portal.
• OAuthClientSecret: The Client secret associated with the OAuth application. You can find this on the Applications page in the Cvent Developer Portal.

Click "Test Connection" to ensure that the DSN is connected to Cvent properly. Navigate to the Tables tab to review the table definitions for Cvent.

Create an External Data Source for Cvent Data

After configuring the connection, you need to create a master encryption key and a credential database for the external data source.

Creating a Master Encryption Key

Execute the following SQL command to create a new master key, 'ENCRYPTION,' to encrypt the credentials for the external data source.

CREATE MASTER KEY ENCRYPTION BY PASSWORD = 'password';

Creating a Credential Database

Execute the following SQL command to create credentials for the external data source connected to Cvent data.

NOTE: Since Cvent does not require a User or Password to authenticate, you may use whatever values you wish for IDENTITY and SECRET.

CREATE DATABASE SCOPED CREDENTIAL cvent_creds
WITH IDENTITY = 'username', SECRET = 'password';

Create an External Data Source for Cvent

Execute a CREATE EXTERNAL DATA SOURCE SQL command to create an external data source for Cvent with PolyBase:

• Set the LOCATION parameter , using the DSN and credentials configured earlier.

For Cvent, set SERVERNAME to the URL or address for your server (e.g. 'localhost' or '127.0.0.1' for local servers; the remote URL for remote servers). Leave PORT empty. PUSHDOWN is set to ON by default, meaning the ODBC Driver can leverage server-side processing for complex queries.

CREATE EXTERNAL DATA SOURCE cdata_cvent_source
WITH ( 
  LOCATION = 'odbc://SERVER_URL',
  CONNECTION_OPTIONS = 'DSN=CData Cvent Sys',
  -- PUSHDOWN = ON | OFF,
  CREDENTIAL = cvent_creds
);

Create External Tables for Cvent

After creating the external data source, use CREATE EXTERNAL TABLE statements to link to Cvent data from your SQL Server instance. The table column definitions must match those exposed by the CData ODBC Driver for Cvent. You can refer to the Tables tab of the DSN Configuration Wizard to see the table definition.

Sample CREATE TABLE Statement

The statement to create an external table based on a Cvent Events would look similar to the following:

CREATE EXTERNAL TABLE Events(
  Id [nvarchar](255) NULL,
  Title [nvarchar](255) NULL,
  ...
) WITH ( 
  LOCATION='Events',
  DATA_SOURCE=cdata_cvent_source
);

Having created external tables for Cvent in your SQL Server instance, you are now able to query local and remote data simultaneously. Thanks to built-in query processing in the CData ODBC Driver, you know that as much query processing as possible is being pushed to Cvent, freeing up local resources and computing power. Download a free, 30-day trial of the ODBC Driver for Cvent and start working with live Cvent data alongside your SQL Server data today.