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  1. Preface
  2. The Transformation Language
  3. Constants
  4. Operators
  5. Dates
  6. Functions
  7. Creating Custom Functions
  8. Custom Function API Reference
  9. POWERCENTERHELP

Transformation Language Reference

Transformation Language Reference

NULL

NULL

Indicates that a value is either unknown or undefined. NULL is not equivalent to a blank or empty string (for character columns) or 0 (for numerical columns).
Although you can write expressions that return nulls, any column that has the NOT NULL or PRIMARY KEY constraint will not accept nulls. Therefore, if the
PowerCenter Integration Service
tries to write a null value to a column with one of these constraints, the database will reject the row and the
PowerCenter Integration Service
will write it to the reject file. Be sure to consider nulls when you create transformations.
Functions can handle nulls differently. If you pass a null value to a function, it might return 0 or NULL, or it might ignore null values.