# Tips for maintaining many-to-one relationships across multiple tables

**URL:** <https://forum.datacebo.com/t/tips-for-maintaining-many-to-one-relationships-across-multiple-tables/219>\
**Category:** Synthetic Data Creation\
**Tags:** multi-table\
**Created:** [July 2, 2024, 12:29am UTC](https://forum.datacebo.com/t/tips-for-maintaining-many-to-one-relationships-across-multiple-tables/219 "2024-07-02T00:29:52Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![ecastaner](https://avatars.discourse-cdn.com/v4/letter/e/2acd7d/32.png) [@ecastaner](https://forum.datacebo.com/u/ecastaner)\
**Post date:** [July 2, 2024, 12:29am UTC](https://forum.datacebo.com/t/tips-for-maintaining-many-to-one-relationships-across-multiple-tables/219/1 "2024-07-02T00:29:52Z")

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@giovanni.circo could you please add a short description of the challenges you’re facing?

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**Author:** ![neha](https://yyz2.discourse-cdn.com/flex030/user_avatar/forum.datacebo.com/neha/32/15_2.png) [@neha](https://forum.datacebo.com/u/neha)\
**Post date:** [January 26, 2026, 9:13pm UTC](https://forum.datacebo.com/t/tips-for-maintaining-many-to-one-relationships-across-multiple-tables/219/2 "2026-01-26T21:13:33Z")

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SDV synthesizers are able to handle one-to-many relationships by default. Make sure that the primary and foreign key connection is listed in your [metadata](https://docs.sdv.dev/sdv/concepts/metadata) and watch SDV do the rest!

### SDV Guarantee

SDV guarantees **referential integrity** , meaning that all the foreign keys will reference a known primary key – no missing links/broken references.

In a one-to-many relationship, the **cardinality** refers to the number of connections between a parent and child. For example, each row of the parent table may be referenced by 0 or more rows in the child table. The SDV synthesizers are also set up to learn:

- The min cardinality (eg. each parent row must be referenced by at least 1 child row)
- The max cardinality (eg. each parent rows must be referenced by at most 5 child rows)
- The distribution in between (eg. most parent rows are referenced by 2 children)

Measure the SDV guarantee using the [Diagnostic Report](https://docs.sdv.dev/sdmetrics/data-metrics/diagnostic/diagnostic-report/multi-table-api) and let us know if you have any feedback!