Error Handling

Handling errors in a transformation ..

Workshop - Error Handling

Bad data happens. Don’t fail the whole transformation because of a few rows. Route error rows to a separate stream for review and cleanup.

What you’ll do

• Read a CSV with a date field
• Trigger a controlled date parsing error
• Configure an error hop to capture failing rows
• Review the error metadata fields (description, field name, error code)
• Fix the date format and verify success

Prerequisites: Complete the Hello World and Logging workshops

Estimated time: 10 minutes

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Error handling

Workshop files

Download the following files.

Keep the filenames unchanged.

Save them in your workshop folder.

customers-100-with-errors.txt

8KB

Open

Create a new transformation

Use any of these options to open a new transformation tab:

• Select File > New > Transformation
• Use Ctrl+N (Windows/Linux) or Cmd+N (macOS)

1. CSV file input

CSV file input

The CSV File Input step reads data from delimited text files into a PDI transformation. While this step is called CSV File Input, you can also use CSV File Input with many other separator types, such as pipes, tabs, and semicolons.

Note: The semicolon (;) is set as the default separator type for this step.

1. Double-click to edit the CSV file input step.

CSV file input

1. Set the following metadata properties for: birthdate

Fieldname	Type	Format
birthdate	date	yyyy/MM/dd

If your CSV uses a different date pattern, keep yyyy/MM/dd for now. This mismatch is what triggers the error rows in the next step.

2. Error hop

Error hop

An error hop routes rows that fail in a step to a separate target step. This lets you keep processing valid rows. You also get extra error fields in the error stream.

1. Double-click the white diagonal cross on the red error hop.

Hop - Error handling

1. Set the error field names (you can pick your own).

• Nr of errors fieldname: Number of errors for the row.
• Error descriptions fieldname: Human-readable error message.
• Error field fieldname: The field that caused the error.
• Error codes fieldname: A code you can filter or group by.

3. Run

Run the transformation

Preview both streams. One contains valid rows. One contains error rows plus error metadata.

1. Select Run in the canvas toolbar.
2. Preview the Dummy step:

Correct birthdate format

1. Preview the Dummy - Errors step:

Errors for incorrectly formatted birthdates

1. Scroll to the end of the Execution results pane.

Use errorCodes to route errors into targeted cleanup logic.

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Fix the format and verify

1. Open CSV file input again.
2. Update the Format value for birthdate to match your CSV.

Example: if your data looks like 2026-02-17, use yyyy-MM-dd.

1. Run the transformation again.
2. Preview Dummy - Errors. You should see fewer rows, or none.

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