Table of Contents

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  1. Preface
  2. Working with Transformations
  3. Aggregator Transformation
  4. Custom Transformation
  5. Custom Transformation Functions
  6. Data Masking Transformation
  7. Data Masking Examples
  8. Expression Transformation
  9. External Procedure Transformation
  10. Filter Transformation
  11. HTTP Transformation
  12. Identity Resolution Transformation
  13. Java Transformation
  14. Java Transformation API Reference
  15. Java Expressions
  16. Java Transformation Example
  17. Joiner Transformation
  18. Lookup Transformation
  19. Lookup Caches
  20. Dynamic Lookup Cache
  21. Normalizer Transformation
  22. Rank Transformation
  23. Router Transformation
  24. Sequence Generator Transformation
  25. Sorter Transformation
  26. Source Qualifier Transformation
  27. SQL Transformation
  28. Using the SQL Transformation in a Mapping
  29. Stored Procedure Transformation
  30. Transaction Control Transformation
  31. Union Transformation
  32. Unstructured Data Transformation
  33. Update Strategy Transformation
  34. XML Transformations

Transformation Guide

Transformation Guide

Step 3. Designate a Return Value

Step 3. Designate a Return Value

You can pass multiple input values into a Lookup transformation and return one column of data. Do not configure the lookup policy to use all values on multiple matches for an unconnected Lookup transformation. Designate one lookup/output port as a return port. You can choose to use the first, last, or any value that matches the lookup condition.
If you call the unconnected lookup from an update strategy or filter expression, you are generally checking for null values. In this case, the return port can be anything. If you call the lookup from an expression performing a calculation, the return value needs to be the value you want to include in the calculation.
To continue the update strategy example, you can define the ITEM_ID port as the return port. The update strategy expression checks for null values returned. If the lookup condition is true, the Integration Service returns the ITEM_ID. If the condition is false, the Integration Service returns NULL.
The following figure shows a return port in a Lookup transformation:
The Ports tab in the Edit Transformations dialog box contains the port name, datatype, precision, scale, input, output, lookup, return, and associated port columns. The ITEM_ID port is the return port. The Ports tab also contains the Select transformation, Transformation type, Default value, and Description fields.

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