--- title: "Non-Identified Relationship — Definition & Guide | OWOX" canonical: "https://www.owox.com/glossary/non-identifying-relationship" updated: "2025-07-03" --- # What Is a Non-Identified Relationship? A non-identifying relationship links two entities without making the child dependent on the parent's primary key. **2 min** read · Updated July 3, 2025 · [Data Modeling](/blog/topics/data-modeling) Non-Identified Relationship means the child entity can exist independently and keeps its own primary key without incorporating the parent’s key. Instead, the foreign key from the parent is added as a separate, non-primary column in the child table, allowing for flexible joins and optional relationships. ## **Core Characteristics of Non-Identifying Relationships** Non-identifying relationships play a key role in database normalization and flexibility. Here are some core traits: * The child table retains its own primary key, independent of the parent. * The foreign key from the parent table is stored in the child as a regular field. * These relationships support optional participation, meaning a child can exist without a related parent. * Used where the child entity does not rely on the parent’s identity for its definition. ## **Types of Non-Identifying Relationships** Non-identifying relationships can be further classified based on the level of dependency they enforce. There are two common types: * **Optional Non-Identifying Relationship**: The child may or may not reference a parent entity. Example: a “PromoCode” table referencing a “Customer” only when a code is used. * **Mandatory Non-Identifying Relationship**: The child must reference a parent, but still has its own independent identity. Example: an “Invoice” must be tied to a “Customer,” but has its own primary key. ## The Turning Point OWOX Data Marts See your first report built in real time. _15 minutes._ 1. Connect your data warehouse 2. Pick your metrics 3. Get a live Google Sheets report In the time it takes to write a ticket. Then imagine never writing that ticket again. [Book a Demo](https://www.owox.com/demo) We'll use your actual use case ## **Identifying vs. Non-Identifying Relationships: Key Differences** While both relationship types connect tables, they differ in how tightly coupled the entities are: * **Primary Key Dependency**: Identifying relationships embed the parent key into the child’s primary key. Non-identifying relationships do not. * **Participation**: Identifying relationships imply total participation (child cannot exist without parent), whereas non-identifying relationships allow for optional links. * **Database Design Use**: Use identifying for tightly bound data (e.g., Order and OrderItems). Use non-identifying when entities can stand alone. ## **Real-World Examples of Non-Identifying Relationships** Here are a few everyday scenarios: * A “Customer” and “Order” table, where each order references a customer but has its own ID. * A “Student” table is linked to a “Club” table, where a student may belong to one or more clubs, but clubs do not define the student’s existence. * A “BlogPost” linked to an optional “Author”—posts remain valid even without a named author. Non-identifying relationships give database designers the flexibility to decouple entities while preserving referential integrity between tables. By not embedding the parent key into the child’s primary key, these relationships allow the child entity to exist on its own while still referencing the parent when needed. This setup is especially useful for modeling optional associations and loosely linked records, resulting in systems that are easier to scale and maintain. ## **Define and Track Non-Identified Relationships with OWOX Data Marts** Handling non-identified relationships can get tricky when connections between tables aren’t explicitly defined through keys. With [**OWOX Data Marts**](https://www.owox.com/app-signup), analysts can establish clear logic for these relationships at the modeling stage, ensuring consistent joins and accurate insights across every dataset. Centralized definitions prevent mismatched results and maintain governance across reports. Bring structure to complex relationships and get started for free. ## Topics [Glossary](/glossary) [Data Modeling](/blog/topics/data-modeling) ## Related terms [What Is an Entity in Data Modeling? Definition](/glossary/entity) [Data Flow Diagram](/glossary/data-flow-diagram) [What Is Data Value? How to Measure & Maximize It](/glossary/data-value) [Data Confidentiality](/glossary/data-confidentiality) [Abstraction in Data Modeling](/glossary/abstraction-in-data-modeling) [ACID Compliance](/glossary/acid-compliance) ## Related articles ## Learn more about analytics [data modeling · Conceptual Data Modeling Explained: An In-Depth Look with Examples · Apr 10, 2025](/blog/articles/conceptual-data-modeling-with-examples) [data modeling · Types of Data Models and Data Modeling Techniques in DBMS · Apr 23, 2025](/blog/articles/types-of-data-models-and-benefits) [data modeling · Logical vs. Physical Data Models: 10 Main Differences Explained · Mar 31, 2025](/blog/articles/logical-vs-physical-data-models) ## Customer stories ## Learn how teams ship analytics faster Organizations that scaled analytics without scaling headcount [All case studies →](/blog/success-stories) [Purblack · "For 10 years I was blind." The day Pürblack® founder stopped guessing · Seconds · to get reports across six channels · Read the story](/blog/success-stories/purblack) [Reformation · How OWOX Reports Helped Reformation Make Data-Backed Decisions · Minutes · from data request to business decision · Read the story](/blog/success-stories/reformation) [WorkSimpli · How OWOX Reports Streamlined Operations for WorkSimpli, Saving Over 10 Hours Weekly · 10hrs+ · saved per week on manual reporting · Read the story](/blog/success-stories/worksimpli) ## What users are saying ## Not testimonials. Comment threads. Real things real customers said — each quote pinned to a specific claim, straight from the quotes database. A3 · re: trusting AI ![Nodari Rizun](https://cdn.owox.ai/www/webflow/6a7b298b2ca5055443187566_nodari-headshot.png/public) Nodari Rizun · Founder & CEO, Pürblack® > _“AI, by the nature of the models, will hallucinate. And because of that, you need something which will create guardrails to ensure that there are no hallucinations, that you can trust your data.”_ C5 · re: opened eyes ![Nodari Rizun](https://cdn.owox.ai/www/webflow/6a7b298b2ca5055443187566_nodari-headshot.png/public) Nodari Rizun · Founder & CEO, Pürblack® > _“I was blind, now I can see. OWOX opened our eyes.”_ E9 · re: results and support PandaDoc · Analytics team > _“We are extremely satisfied with the results achieved through our partnership with OWOX. I'm also impressed by quick and effective support we get from OWOX”_ ## Your New Normal Turn your data into decisions. Governed data marts give you the clean foundation ML needs to actually work. * No AI hallucinations * Analyst-governed definitions * Every number traces to SQL [Get started free](https://www.owox.com/app-signup) ## References Pages this page links to, on this site and on docs.owox.com. Where the page has a Markdown twin, its address follows the link. - [Data Modeling](https://www.owox.com/blog/topics/data-modeling) — /blog/topics/data-modeling.md - [Book a Demo](https://www.owox.com/demo) — /demo.md - [OWOX Data Marts](https://www.owox.com/app-signup) - [Glossary](https://www.owox.com/glossary) — /glossary.md - [What Is an Entity in Data Modeling? Definition](https://www.owox.com/glossary/entity) — /glossary/entity.md - [Data Flow Diagram](https://www.owox.com/glossary/data-flow-diagram) — /glossary/data-flow-diagram.md - [What Is Data Value? How to Measure & Maximize It](https://www.owox.com/glossary/data-value) — /glossary/data-value.md - [Data Confidentiality](https://www.owox.com/glossary/data-confidentiality) — /glossary/data-confidentiality.md - [Abstraction in Data Modeling](https://www.owox.com/glossary/abstraction-in-data-modeling) — /glossary/abstraction-in-data-modeling.md - [ACID Compliance](https://www.owox.com/glossary/acid-compliance) — /glossary/acid-compliance.md - [data modeling · Conceptual Data Modeling Explained: An In-Depth Look with Examples · Apr 10, 2025](https://www.owox.com/blog/articles/conceptual-data-modeling-with-examples) — /blog/articles/conceptual-data-modeling-with-examples.md - [data modeling · Types of Data Models and Data Modeling Techniques in DBMS · Apr 23, 2025](https://www.owox.com/blog/articles/types-of-data-models-and-benefits) — /blog/articles/types-of-data-models-and-benefits.md - [data modeling · Logical vs. Physical Data Models: 10 Main Differences Explained · Mar 31, 2025](https://www.owox.com/blog/articles/logical-vs-physical-data-models) — /blog/articles/logical-vs-physical-data-models.md - [All case studies →](https://www.owox.com/blog/success-stories) — /blog/success-stories.md - [Purblack · "For 10 years I was blind." The day Pürblack® founder stopped guessing · Seconds · to get…](https://www.owox.com/blog/success-stories/purblack) — /blog/success-stories/purblack.md - [Reformation · How OWOX Reports Helped Reformation Make Data-Backed Decisions · Minutes · from data…](https://www.owox.com/blog/success-stories/reformation) — /blog/success-stories/reformation.md - [WorkSimpli · How OWOX Reports Streamlined Operations for WorkSimpli, Saving Over 10 Hours Weekly ·…](https://www.owox.com/blog/success-stories/worksimpli) — /blog/success-stories/worksimpli.md