Detects duplicate features based on the value of one or more key attributes.

Usage Notes

  • This is a more specific type of operation than that provided by the Matcher, which can match on multiple attributes as well as geometry. For such situations, this transformer is dramatically more efficient than the Matcher.
  • Output feature order may be controlled with the Advanced > Preserve Feature Order parameter.


Output Ports

This transformer outputs to the Duplicate port any feature whose key attribute value is the same as one previously encountered. Any feature whose key value has not yet appeared is output via the Unique port.

The first feature with a unique key value is output via the Unique port – and subsequent features that have the same key value are output via the Duplicate port.


Editing Transformer Parameters

Using a set of menu options, transformer parameters can be assigned by referencing other elements in the workspace. More advanced functions, such as an advanced editor and an arithmetic editor, are also available in some transformers. To access a menu of these options, click beside the applicable parameter. For more information, see Transformer Parameter Menu Options.

Defining Values

There are several ways to define a value for use in a Transformer. The simplest is to simply type in a value or string, which can include functions of various types such as attribute references, math and string functions, and workspace parameters. There are a number of tools and shortcuts that can assist in constructing values, generally available from the drop-down context menu adjacent to the value field.

Dialog Options - Tables

Transformers with table-style parameters have additional tools for populating and manipulating values.

FME Community

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