Value Mapper

Value Mapper

Description

The Value Mapper transform maps string values from one value to another.

Mapping is usually solved by storing the conversion table in a database.

The Value Mapper provides you with a simple alternative.

For example, if you want to replace language codes:

Fieldname to use: LanguageCode
Target fieldname: LanguageDesc
Source/Target: EN/English, FR/French, NL/Dutch, ES/Spanish, DE/German, ...

Hop Engine	✓
Spark	?
Flink	?
Dataflow	?

Options

The following properties are used to define the mappings:

Option	Description
Transform Name	Name of the transform this name has to be unique in a single pipeline.
Fieldname to use	Field to use as the mapping source
Target field name	Field to use as the mapping Target
Default upon non-matching	Defines a default value for situations where the source value is not empty, but there is no match
Field values table	Contains the mapping of source value to converted target value.

Mapping NULL values

If there is an empty source value defined, NULLs and empty strings are mapped to the corresponding target value. Only one empty mapping is allowed.

If the input stream contains NULL values, and no mapping for NULLs is defined, NULL is returned (and not the default target)