Connect to Excel Online Data as an External Data Source using PolyBase

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 Excel Online, you get access to your Excel Online data directly alongside your SQL Server data. This article describes creating an external data source and external tables to grant access to live Excel Online data using T-SQL queries.

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

CData Connect AI provides a pure SQL Server interface for Excel Online, allowing you to query data from Excel Online without replicating the data to a natively supported database. Using optimized data processing out of the box, CData Connect AI pushes all supported SQL operations (filters, JOINs, etc.) directly to Excel Online, leveraging server-side processing to return the requested Excel Online data quickly.

Configure Excel Online Connectivity for PolyBase

Connectivity to Excel Online from PolyBase is made possible through CData Connect AI. To work with Excel Online data from PolyBase, we start by creating and configuring a Excel Online connection.

1. Log into Connect AI, click Sources, and then click Add Connection
👁 Adding a Connection

2. Select "Excel Online" from the Add Connection panel
👁 Selecting a data source

3. Enter the necessary authentication properties to connect to Excel Online.

   You can connect to a workbook by providing authentication to Excel Online and then setting the following properties:

   • : Set this to the name or Id of the workbook.

     If you want to view a list of information about the available workbooks, execute a query to the Workbooks view after you authenticate.

   • : Set this to true if you are connecting to a workbook in a sandbox account. Otherwise, leave this blank to connect to a production account.

   You use the OAuth authentication standard to authenticate to Excel Online. See the Getting Started section in the help documentation for a guide. Getting Started also guides you through executing SQL to worksheets and ranges.

   👁 Configuring a connection (Salesforce is shown)
   
4. Click Save & Test
5. Navigate to the Permissions tab in the Add Excel Online Connection page and update the User-based permissions. 👁 Updating permissions
   

Add a Personal Access Token

When connecting to Connect AI through the REST API, the OData API, or the Virtual SQL Server, a Personal Access Token (PAT) is used to authenticate the connection to Connect AI. It is best practice to create a separate PAT for each service to maintain granularity of access.

1. Click on the Gear icon () at the top right of the Connect AI app to open the settings page.
2. On the Settings page, go to the Access Tokens section and click Create PAT.
3. Give the PAT a name and click Create. 👁 Creating a new PAT
   
4. The personal access token is only visible at creation, so be sure to copy it and store it securely for future use.

With the connection configured and a PAT generated, you are ready to connect to Excel Online data from Polybase.

Create an External Data Source for Excel Online Data

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

Creating a Credential Database

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

NOTE: Set IDENTITY to your Connect AI username and set SECRET to your Personal Access Token.

CREATE DATABASE SCOPED CREDENTIAL ConnectCloudCredentials
WITH IDENTITY = 'yourusername', SECRET = 'yourPAT';

Create an External Data Source for Excel Online

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

CREATE EXTERNAL DATA SOURCE ConnectCloudInstance
WITH ( 
 LOCATION = 'sqlserver://tds.cdata.com:14333',
 PUSHDOWN = ON,
 CREDENTIAL = ConnectCloudCredentials
);

Create External Tables for Excel Online

After creating the external data source, use CREATE EXTERNAL TABLE statements to link to Excel Online data from your SQL Server instance. The table column definitions must match those exposed by CData Connect AI. You can use the Data Explorer in Connect AI to see the table definition.

👁 Table definition in the Data Explorer (Salesforce is shown)

Sample CREATE TABLE Statement

Execute a CREATE EXTERNAL TABLE SQL command to create the external table(s), using the collation and setting the LOCATION to three-part notation for the connection, catalog, and table. The statement to create an external table based on a Excel Online Test_xlsx_Sheet1 would look similar to the following.

CREATE EXTERNAL TABLE Test_xlsx_Sheet1(
 Id COLLATE [nvarchar](255) NULL,
 Column1 COLLATE [nvarchar](255) NULL,
 ...
) WITH ( 
 LOCATION='ExcelOnline1.ExcelOnline.Test_xlsx_Sheet1',
 DATA_SOURCE=ConnectCloudInstance
);

Having created external tables for Excel Online in your SQL Server instance, you are now able to query local and remote data simultaneously. To get live data access to hundreds of SaaS, Big Data, and NoSQL sources directly from your SQL Server database, try CData Connect AI today!