Table of Contents

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  1. Preface
  2. Transformations
  3. Source transformation
  4. Target transformation
  5. Aggregator transformation
  6. Cleanse transformation
  7. Data Masking transformation
  8. Data Services transformation
  9. Deduplicate transformation
  10. Expression transformation
  11. Filter transformation
  12. Hierarchy Builder transformation
  13. Hierarchy Parser transformation
  14. Hierarchy Processor transformation
  15. Input transformation
  16. Java transformation
  17. Java transformation API reference
  18. Joiner transformation
  19. Labeler transformation
  20. Lookup transformation
  21. Machine Learning transformation
  22. Mapplet transformation
  23. Normalizer transformation
  24. Output transformation
  25. Parse transformation
  26. Python transformation
  27. Rank transformation
  28. Router transformation
  29. Rule Specification transformation
  30. Sequence Generator transformation
  31. Sorter transformation
  32. SQL transformation
  33. Structure Parser transformation
  34. Transaction Control transformation
  35. Union transformation
  36. Velocity transformation
  37. Verifier transformation
  38. Web Services transformation

Transformations

Transformations

Expression fields

Expression fields

An expression field defines the calculations to perform on an incoming field and acts as the output field for the results. You can use as many expression fields as necessary to perform calculations on incoming fields.
When you configure an expression field, you define different fields based on the field type, for example the field name, data type, precision, scale, default value, and optional description. The description can contain up to 4000 characters. You also define the calculations that you want to perform.
You cannot specify an expression decimal field precision value greater than 38.

Effect of the default value

The default value tells the mapping task what to do when the transformation encounters output errors. The default value is not available in mappings in advanced mode.
You can set one of the following values for output fields:
  • ERROR('transformation error'). System default. When a transformation error occurs, the mapping task skips the row and writes the error to the session log or row error log.
  • A constant or constant expression. The mapping task replaces the error with the constant or constant expression. Nothing is written to the logs.
  • ABORT. Transformation aborts and the mapping task writes a message to the session log.
Data Integration validates the output field default value when you save or validate the mapping. If you enter an invalid default value, the Mapping Designer marks the mapping as not valid.

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