How to Build an ETL App for HCL Domino Data in Python with CData

The rich ecosystem of Python modules lets you get to work quickly and integrate your systems more effectively. With the CData Python Connector for HCL Domino and the petl framework, you can build HCL Domino-connected applications and pipelines for extracting, transforming, and loading HCL Domino data. This article shows how to connect to HCL Domino with the CData Python Connector and use petl and pandas to extract, transform, and load HCL Domino data.

With built-in, optimized data processing, the CData Python Connector offers unmatched performance for interacting with live HCL Domino data in Python. When you issue complex SQL queries from HCL Domino, the driver pushes supported SQL operations, like filters and aggregations, directly to HCL Domino and utilizes the embedded SQL engine to process unsupported operations client-side (often SQL functions and JOIN operations).

Connecting to HCL Domino Data

Connecting to HCL Domino data looks just like connecting to any relational data source. Create a connection string using the required connection properties. For this article, you will pass the connection string as a parameter to the create_engine function.

Prerequisites

The connector requires the Proton component to be installed. Normally, Proton is distributed as part of the AppDev pack. See the HCL documentation for instructions on acquiring and installing Proton or the AppDev pack.

Once the Proton service is installed and running, you will also need to create a user account and download its Internet certificate. This certificate can be used to set the connector certificate connection properties.

Authenticating to Domino

• Server: The name or IP address of the server running Domino with the Proton service.
• Port: The port number that the Proton service is listening on.
• Database: The name of the database file, including the .nsf extension.
• SSLClientCertType: This must match the format of the certificate file. Typically this will be either PEMKEY_FILE for .pem certificates or PFXFILE for .pfx certificates.
• SSLClientCert: The path to the certificate file.
• SSLServerCert: This can be set to (*) if you trust the server. This is usually the case, but if you want to perform SSL validation, you may provide a certificate or thumbprint instead. See the documentation for SSLServerCert for details.

Additional Server Configuration

The connector supports querying Domino views if any are defined. Before views can be queried by the connector they must be registered with the design catalog.

Please refer to the Catalog Administration section of the AppDev pack documentation for details on how to do this.

After installing the CData HCL Domino Connector, follow the procedure below to install the other required modules and start accessing HCL Domino through Python objects.

Install Required Modules

Use the pip utility to install the required modules and frameworks:

pip install petl
pip install pandas

Build an ETL App for HCL Domino Data in Python

Once the required modules and frameworks are installed, we are ready to build our ETL app. Code snippets follow, but the full source code is available at the end of the article.

First, be sure to import the modules (including the CData Connector) with the following:

import petl as etl
import pandas as pd
import cdata.domino as mod

You can now connect with a connection string. Use the connect function for the CData HCL Domino Connector to create a connection for working with HCL Domino data.

cnxn = mod.connect("Server=https://domino.corp.com;Database=names.nsf;Port=3002;SSLClientCertType=PEMKEY_FILE;SSLClientCert=full_path_of_certificate.pem;SSLServerCert=*")

Create a SQL Statement to Query HCL Domino

Use SQL to create a statement for querying HCL Domino. In this article, we read data from the ByName entity.

sql = "SELECT Name, Address FROM ByName WHERE City = 'Miami'"

Extract, Transform, and Load the HCL Domino Data

With the query results stored in a DataFrame, we can use petl to extract, transform, and load the HCL Domino data. In this example, we extract HCL Domino data, sort the data by the Address column, and load the data into a CSV file.

Loading HCL Domino Data into a CSV File

table1 = etl.fromdb(cnxn,sql)

table2 = etl.sort(table1,'Address')

etl.tocsv(table2,'byname_data.csv')

With the CData Python Connector for HCL Domino, you can work with HCL Domino data just like you would with any database, including direct access to data in ETL packages like petl.

Free Trial & More Information

Download a free, 30-day trial of the CData Python Connector for HCL Domino to start building Python apps and scripts with connectivity to HCL Domino data. Reach out to our Support Team if you have any questions.

Full Source Code

import petl as etl
import pandas as pd
import cdata.domino as mod

cnxn = mod.connect("Server=https://domino.corp.com;Database=names.nsf;Port=3002;SSLClientCertType=PEMKEY_FILE;SSLClientCert=full_path_of_certificate.pem;SSLServerCert=*")

sql = "SELECT Name, Address FROM ByName WHERE City = 'Miami'"

table1 = etl.fromdb(cnxn,sql)

table2 = etl.sort(table1,'Address')

etl.tocsv(table2,'byname_data.csv')