Nested mapping is how Etlworks maps source fields to destination fields when either side (or both) is a nested document — JSON, XML, EDI, or other hierarchical formats. It uses a unified mechanism that handles flat-to-nested, nested-to-flat, and nested-to-nested patterns with the same configuration model.
The full reference for nested mapping lives in the Mapping section, since it's a feature of the mapping editor rather than a separate transformation type.
Read the full coverage: Nested mapping — overview of the unified mechanism, difference between nested and flat, automatic flattening, drag-and-drop reference, and the full source/destination control map.
When to reach for nested mapping
- You're loading a JSON / XML / EDI response into a flat table and need control over how the hierarchy unwinds.
- You're building a nested payload (JSON or XML) for an API call from one or more flat sources.
- You're transforming one nested structure into a different nested structure (e.g., reshape an HL7 message into a custom JSON shape).
Related patterns in this category
- Flatten and Normalize Nested Documents — when the destination is flat.
- Articles in this section — when the destination is nested.