---
title: DVLINK_ForeignKey_Identity
description: DVLINK_ForeignKey_Identity is the hash foreign key of a Link to one of its Hubs.
---

[Skip to content](https://knowledge.bigenius-x.com/dvlink_foreignkey_identity#main-content)

[Contact us](https://knowledge.bigenius-x.com/kb-tickets/new?hsLang=en) [Go to Customer Portal](https://knowledge.bigenius-x.com/customer-portal?hsLang=en)

[![TRI\_Logo\_biGENIUS\_2020\_RGB\_s](https://knowledge.bigenius-x.com/hs-fs/hubfs/Marketing/TRI_Logo_biGENIUS_2020_RGB_s.png?width=150&height=42&name=TRI_Logo_biGENIUS_2020_RGB_s.png)](https://www.bigenius-x.com/)

Open main navigation

Close main navigation

- [Contact us](https://knowledge.bigenius-x.com/kb-tickets/new)
- [Go to Customer Portal](https://knowledge.bigenius-x.com/customer-portal)

 How can we help you?

- There are no suggestions because the search field is empty.

1. [biGENIUS-X Knowledge Base](https://knowledge.bigenius-x.com/?hsLang=en)
2. [Generators](https://knowledge.bigenius-x.com/generators?hsLang=en)
3. [Default Terms](https://knowledge.bigenius-x.com/generators?hsLang=en#default-terms)

# DVLINK\_ForeignKey\_Identity

**Applies to**  
Platform: Microsoft SQL Server · Snowflake · Snowflake dbt · Databricks · Databricks dbt · Fabric Lakehouse · Fabric Warehouse · Oracle  
Architecture: Data Vault

`DVLINK_ForeignKey_Identity` is the hash foreign key of a Link to one of its Hubs. A Link has one such term per Hub relationship, and its value equals the `Hub_HK` of the referenced Hub row.

### Objects that carry it

Link, Driving Key Link, Hierarchical Link, Same As Link and their Business Vault counterparts. The term is created for each relationship from the Link to a Hub, not when the Link itself is created.

Its name has the form `<Hub name>_<role>_HK` in the generated tables, for example `common_employee_EMPLOYEE_HK`. Here `<Hub name>` is the referenced Hub and `<role>` the role of the relationship.

### Value

The Hashing view hashes the foreign-key terms of the relationship in the term order of the Hub, with the project [Hash Algorithm](https://knowledge.bigenius-x.com/hash-algorithm-project?hsLang=en). The Hub hashes its business keys in the same way, so both values match.

When all foreign-key terms of the relationship are nullable and all of them are NULL, the value is the unknown-member key of zero bytes. Projects that still use the setting Nulled Business Keys Point to Non-Existing Hub Key of [Behaviour for Nulled Business Keys in Links](https://knowledge.bigenius-x.com/behaviour-for-nulled-business-keys-in-links?hsLang=en) hash the NULL values instead.

### Data type

| Platform | Type |
| --- | --- |
| Microsoft SQL Server | `binary(20)` |
| Fabric Warehouse | `varbinary(20)` |
| Oracle | `RAW(20)` |
| Snowflake, Snowflake dbt | `BINARY(32)` |
| Databricks, Databricks dbt, Fabric Lakehouse | `binary` |

The data type must match the length of the selected [Hash Algorithm](https://knowledge.bigenius-x.com/hash-algorithm-project?hsLang=en).

### Example

A Driving Key Link on Microsoft SQL Server references an employee Hub with the role `EMPLOYEE`. Its Hashing view calculates:

```
CAST(HASHBYTES('SHA1', CAST('' AS VARCHAR(MAX))
    + ISNULL(CAST([FK_common_employee_EMPLOYEE_EMPLOYEE_ID]
        AS NVARCHAR(4000)), N'_NULL_'))
    AS VARBINARY(20)) AS [common_employee_EMPLOYEE_HK]
```

For employee 7 the Link row holds `0x7402F76B2D6078A455F77607AF6E7350B6DE019E`. The Multi-Active Satellite of the employee Hub stores the same value as `Hub_HK` for employee 7.

### Release differences

- Generator 2.4: Snowflake uses SHA2-256 with `BINARY(32)` by default. Up to Generator 2.3 the default was `HASH` with a numeric type, see [Generators Release - 2.4.0](https://knowledge.bigenius-x.com/generators-release-2.4.0?hsLang=en).
- Generator 2.2: Databricks and Fabric Lakehouse store hash values as `binary`. Up to Generator 2.0 they were `string`.

### Related articles

- Reference: [Link\_HK](https://knowledge.bigenius-x.com/link_hk?hsLang=en), [Hub\_HK](https://knowledge.bigenius-x.com/hub_hk?hsLang=en), [Hash Algorithm (Project)](https://knowledge.bigenius-x.com/hash-algorithm-project?hsLang=en), [Behaviour for Nulled Business Keys in Links (Project)](https://knowledge.bigenius-x.com/behaviour-for-nulled-business-keys-in-links?hsLang=en)
- See also: [How biGENIUS-X builds hash values](https://knowledge.bigenius-x.com/how-bigenius-x-builds-hash-values?hsLang=en), [Create a Link](https://knowledge.bigenius-x.com/create-a-link?hsLang=en), [Create a Driving Key Link](https://knowledge.bigenius-x.com/create-a-driving-key-link?hsLang=en)

- [Getting started](https://knowledge.bigenius-x.com/getting-started?hsLang=en#main-content)

    - [Guidelines](https://knowledge.bigenius-x.com/getting-started?hsLang=en#guidelines)
    - [Start working](https://knowledge.bigenius-x.com/getting-started?hsLang=en#start-working)
    - [Account](https://knowledge.bigenius-x.com/getting-started?hsLang=en#account)
- [General overview](https://knowledge.bigenius-x.com/general-overview?hsLang=en)
- [Artificial Intelligence](https://knowledge.bigenius-x.com/artificial-intelligence?hsLang=en)
- [Application Modules](https://knowledge.bigenius-x.com/application-modules?hsLang=en#main-content)

    - [Administration](https://knowledge.bigenius-x.com/application-modules?hsLang=en#administration)
    - [Solutions](https://knowledge.bigenius-x.com/application-modules?hsLang=en#solutions)
    - [Global Features](https://knowledge.bigenius-x.com/application-modules?hsLang=en#global-features)
    - [Projects](https://knowledge.bigenius-x.com/application-modules?hsLang=en#projects)
    - [Branches](https://knowledge.bigenius-x.com/application-modules?hsLang=en#branches)
    - [Data Connections](https://knowledge.bigenius-x.com/application-modules?hsLang=en#data-connections)
    - [Dataflow Modeling - Overview](https://knowledge.bigenius-x.com/application-modules?hsLang=en#dataflow-modeling-overview)
    - [Dataflow Modeling - Wizard Steps](https://knowledge.bigenius-x.com/application-modules?hsLang=en#dataflow-modeling-wizard-steps)
    - [Dataflow Modeling - Terms](https://knowledge.bigenius-x.com/application-modules?hsLang=en#dataflow-modeling-terms)
    - [Dataflow Modeling - Term Mapping](https://knowledge.bigenius-x.com/application-modules?hsLang=en#dataflow-modeling-term-mapping)
    - [Dataflow Modeling - Relationships](https://knowledge.bigenius-x.com/application-modules?hsLang=en#dataflow-modeling-relationships)
    - [Dataflow Modeling - Data Quality](https://knowledge.bigenius-x.com/application-modules?hsLang=en#dataflow-modeling-data-quality)
    - [Dataflow Modeling - Indexes](https://knowledge.bigenius-x.com/application-modules?hsLang=en#dataflow-modeling-indexes)
    - [Relationship Modeling](https://knowledge.bigenius-x.com/application-modules?hsLang=en#relationship-modeling)
    - [Generate Artifacts](https://knowledge.bigenius-x.com/application-modules?hsLang=en#generate-artifacts)
    - [Project Settings](https://knowledge.bigenius-x.com/application-modules?hsLang=en#project-settings)
    - [Data Marketplace](https://knowledge.bigenius-x.com/application-modules?hsLang=en#data-marketplace)
- [Generators](https://knowledge.bigenius-x.com/generators?hsLang=en#main-content)

    - [Fabric Warehouse](https://knowledge.bigenius-x.com/generators?hsLang=en#fabric-warehouse)
    - [Fabric Lakehouse](https://knowledge.bigenius-x.com/generators?hsLang=en#fabric-lakehouse)
    - [Databricks](https://knowledge.bigenius-x.com/generators?hsLang=en#databricks)
    - [Snowflake](https://knowledge.bigenius-x.com/generators?hsLang=en#snowflake)
    - [Microsoft SQL Server](https://knowledge.bigenius-x.com/generators?hsLang=en#microsoft-sql-server)
    - [Artifacts](https://knowledge.bigenius-x.com/generators?hsLang=en#artifacts)
    - [Replace Placeholders](https://knowledge.bigenius-x.com/generators?hsLang=en#replace-placeholders)
    - [Target solution environment](https://knowledge.bigenius-x.com/generators?hsLang=en#target-solution-environment)
    - [Deployment](https://knowledge.bigenius-x.com/generators?hsLang=en#deployment)
    - [Deployment with an Azuze DevOps pipeline](https://knowledge.bigenius-x.com/generators?hsLang=en#deployment-with-an-azuze-devops-pipeline)
    - [Delta Deployment](https://knowledge.bigenius-x.com/generators?hsLang=en#delta-deployment)
    - [Load control environment](https://knowledge.bigenius-x.com/generators?hsLang=en#load-control-environment)
    - [Load data with a native load control](https://knowledge.bigenius-x.com/generators?hsLang=en#load-data-with-a-native-load-control)
    - [Load data with Apache Airflow](https://knowledge.bigenius-x.com/generators?hsLang=en#load-data-with-apache-airflow)
    - [Model Object Type](https://knowledge.bigenius-x.com/generators?hsLang=en#model-object-type)
    - [Properties](https://knowledge.bigenius-x.com/generators?hsLang=en#properties)
    - [Default Terms](https://knowledge.bigenius-x.com/generators?hsLang=en#default-terms)
- [Discovery application](https://knowledge.bigenius-x.com/discovery-application?hsLang=en#main-content)

    - [Discovery configurations](https://knowledge.bigenius-x.com/discovery-application?hsLang=en#discovery-configurations)
- [Best practices](https://knowledge.bigenius-x.com/best-practices?hsLang=en#main-content)

    - [Modeling Approaches](https://knowledge.bigenius-x.com/best-practices?hsLang=en#modeling-approaches)
    - [Use Cases](https://knowledge.bigenius-x.com/best-practices?hsLang=en#use-cases)
    - [Business Rules](https://knowledge.bigenius-x.com/best-practices?hsLang=en#business-rules)
    - [Data Quality Rules](https://knowledge.bigenius-x.com/best-practices?hsLang=en#data-quality-rules)
- [FAQs](https://knowledge.bigenius-x.com/faqs?hsLang=en)
- [Product Release Notes](https://knowledge.bigenius-x.com/product-release-notes?hsLang=en#main-content)

    - [SaaS Application](https://knowledge.bigenius-x.com/product-release-notes?hsLang=en#saas-application)
    - [Discovery application](https://knowledge.bigenius-x.com/product-release-notes?hsLang=en#discovery-application)
    - [Generators](https://knowledge.bigenius-x.com/product-release-notes?hsLang=en#generators)
- [Legal Documents](https://knowledge.bigenius-x.com/legal-documents?hsLang=en#main-content)

    - [Current legal docs](https://knowledge.bigenius-x.com/legal-documents?hsLang=en#current-legal-docs)
    - [Software Product and Limits](https://knowledge.bigenius-x.com/legal-documents?hsLang=en#software-product-and-limits)

- [Contact us](https://knowledge.bigenius-x.com/kb-tickets/new?hsLang=en)
- [Customer Portal](https://knowledge.bigenius-x.com/customer-portal)
- [Sign in](https://knowledge.bigenius-x.com/_hcms/mem/login)

[![biGENIUS logo](https://knowledge.bigenius-x.com/hubfs/TRI_Logo_biGENIUS_2020_RGB-1.svg "biGENIUS logo")](https://www.bigenius-x.com)

<https://www.linkedin.com/company/bigenius> <https://www.youtube.com/@biGENIUS_DWA>

All rights reserved © 2025, biGENIUS AG