I am searching for a tool that is able to display two DIFFERENT nested data structures as a tree side by side and make it possible to display a mapping between them.

The purpose is to make it possible for business people to document how structures relate to each other and for developers to be able to see which data should be mapped to which field in the new or other data structures.

Currenty Excel is in heavy use for this and it is totally inappropriate because nested structures cannot be displayed in a good way.enter image description here

I added a small mockup here, please imagine the data structures are different. Unfortunately we actually have different names for the same things in different business domains so the mapping is not self explained by the names of the properties.

2 Answers 2


I believe GoJS gives you what you are asking for. Look at this sample: https://gojs.net/latest/samples/treeMapper.html enter image description here

You can also have the right side tree facing the other way: https://gojs.net/extras/treeMapperMirrored.html

  • Great Finding! Thank you.
    – Chris
    Commented Sep 7, 2023 at 10:52

The old Microsoft DTS GUI of SQL Server 2000 did exactly this (example pics), up to SQL Server 2005 or so, until DTS was rebranded to SSIS (SQL Server Integration Services).

DTS stands for Data transformation Services.

DTS was an extra, optional, feature on the SQL Server installation CD-ROMs (Similar to Solver in Excel, or Thesaurus in WinWord), but gratis for all versions of SQL Server.

It even proposed one-click automatic insertion of connector lines, where the columnnames matched exactly.

Unfortunately SSIS was then no longer freely included with SQL Server, but instead Microsoft made it part of the paid-for variants of SQL Server. I don't remember. (Correct me if I'm wrong)

Nowadays I use a simple GUI-based diff-editor like Meld , called from the command-line:

meld config.before.json  config.after.json

In the two-pane window then I move matching lines next to each other, inserting empty lines where it is needed, or moving lines by cut-and-paste. (Meld does not draw arrows but uses different background colors for insertions/deletions, similar to a Sankey diagram)

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