Hello World
Simple transformation to illustrate key concepts ..
Workshop - Hello World
Every data integration journey begins with understanding the fundamental building blocks. In this classic "Hello World" workshop, you'll create your first Pentaho transformation from scratch, establishing the essential workflow you'll use throughout your career as a PDI developer.
In this hands-on workshop, you'll learn the core mechanics of building transformations in Spoon by assembling a simple data pipeline. You'll work with steps, hops, and annotations—the three foundational elements that form every transformation—while gaining confidence with the drag-and-drop interface and preview capabilities that make PDI development intuitive and efficient.
What You'll Accomplish:
Create a new transformation from scratch
Add and configure transformation steps (Generate Rows and Dummy)
Connect steps using hops to define data flow
Add notes to document your transformation
Preview data at any step to verify your logic
Execute your transformation and interpret the execution metrics
Understand the Logging and Step Metrics tabs for monitoring
By the end of this workshop, you'll have completed your first working transformation and established a repeatable development workflow: add steps, configure properties, preview data, connect with hops, and run. This pattern will serve as the foundation for building increasingly complex data integration solutions throughout the course.
Prerequisites: Pentaho Data Integration installed and configured
Estimated Time: 10 minutes
Generate Rows
Generate rows outputs a specified number of rows. By default, the rows are empty; however, they can also contain several static fields. This step is used primarily for testing purposes. It may be useful for generating a fixed number of rows, for example, if you require exactly 12 rows for 12 months.
Sometimes you may use Generate Rows to generate one row that is an initiating point for your transformation.
Start Pentaho Data Integration.
To add the Generate Rows step, expand the ‘Input’ category in the Design tab, and drag the step onto the canvas.
💡Alternatively, enter ‘Generate Rows’ into the search bar.
Double-click on the Generate Rows to open step properties.
Ensure the following details are configured:
Step name
gr_hello-world
Limit
10
Name
message
Type
string
Value
hello world
Click Preview button. The ‘Enter preview size’ dialog is displayed.
In the ‘Enter preview size’ dialog, click the [OK] button.
Verify 10 rows of data with the message you entered is displayed, and then click the [OK] button to close the ‘Examine preview data’ dialog.
Click OK button to close the ‘Generate Rows’ dialog.
Dummy
The Dummy step does process records. Its primary function is to be a placeholder for testing purposes. For example, to have a transformation, you need at least two steps connected to each other.
To add the Dummy step, expand the ‘Flow’ category in the Design tab, and drag the Dummy step onto the canvas:
Hops
Hops are the I/O buffer in your data stream.
Steps may be configured with specific I/O parameters to meet requirements.
Click on the hello world step.
Hold down the Shift key.
Drag and drop the hop onto the Dummy step.
Release the Shift key.
Add a Note
Right mouse click anywhere on Spoon canvas.
Select: New Note.
Transformation Properties
To view the transformation properties:
Double-click anywhere on the canvas.
💡Optionally, enter a more detailed description in the ‘Extended description’ property.
In Spoon, select Action > Run This Transformation.
Click Run icon and select Run Options.
The transformation executes.
A green tick confirms the transformation's execution, but doesn't guarantee the success of the underlying operations.
Logging tab displays logging information for each of the steps in the transformation.
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