What is the \'Owning Side\' in Object-Relational Mapping (ORM)?
Understanding the "Owning Side" in ORM Mapping
In Object-Relational Mapping (ORM), the concept of "owning side" refers to the entity that manages the foreign key relationship in a database. This arises because relational databases do not inherently support bidirectional relationships, unlike object-oriented programming.
Necessity of an Owning Side
In ORM, the owning side is responsible for maintaining the integrity of a relationship by owning the foreign key that represents the other entity in the relationship. Without an owning side, each side of the relationship would require a foreign key, leading to unnecessary association tables and potential data duplication.
Ownership in Different Relationship Types
- One-to-Many: The owning side typically contains the foreign key in the child table, allowing multiple children to be associated with a single parent.
- One-to-One: Similar to one-to-many, the owning side holds the foreign key, while the non-owning side uses the mappedBy attribute to indicate the relationship.
- Many-to-One: The owning side holds the foreign key, allowing multiple entities to reference a single parent.
Example: One-to-Many Mapping with Owning Side
Consider the following Java example:
@Entity public class Person { @Id private Long id; @OneToMany(mappedBy = "person") private List<IdDocument> idDocuments; } @Entity public class IdDocument { @Id private Long id; @ManyToOne private Person person; }
In this example, Person is the owning side, as it contains the foreign key that references the IdDocument table. The mappedBy attribute in IdDocument indicates that the relationship is managed by the owning side.
Implications of Using mappedBy
Using mappedBy on the non-owning side shifts the responsibility of managing the relationship to the owning side. This means:
- The foreign key updates must only be performed on the owning side (e.g., idDocument.setPerson(person)).
- Hibernate will not track changes to the relationship on the non-owning side (e.g., person.getIdDocuments().add(idDocument)).
The above is the detailed content of What is the \'Owning Side\' in Object-Relational Mapping (ORM)?. For more information, please follow other related articles on the PHP Chinese website!

Hot AI Tools

Undresser.AI Undress
AI-powered app for creating realistic nude photos

AI Clothes Remover
Online AI tool for removing clothes from photos.

Undress AI Tool
Undress images for free

Clothoff.io
AI clothes remover

Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!

Hot Article

Hot Tools

Notepad++7.3.1
Easy-to-use and free code editor

SublimeText3 Chinese version
Chinese version, very easy to use

Zend Studio 13.0.1
Powerful PHP integrated development environment

Dreamweaver CS6
Visual web development tools

SublimeText3 Mac version
God-level code editing software (SublimeText3)

Hot Topics

Troubleshooting and solutions to the company's security software that causes some applications to not function properly. Many companies will deploy security software in order to ensure internal network security. ...

Field mapping processing in system docking often encounters a difficult problem when performing system docking: how to effectively map the interface fields of system A...

When using MyBatis-Plus or other ORM frameworks for database operations, it is often necessary to construct query conditions based on the attribute name of the entity class. If you manually every time...

Solutions to convert names to numbers to implement sorting In many application scenarios, users may need to sort in groups, especially in one...

Start Spring using IntelliJIDEAUltimate version...

Conversion of Java Objects and Arrays: In-depth discussion of the risks and correct methods of cast type conversion Many Java beginners will encounter the conversion of an object into an array...

Detailed explanation of the design of SKU and SPU tables on e-commerce platforms This article will discuss the database design issues of SKU and SPU in e-commerce platforms, especially how to deal with user-defined sales...

When using TKMyBatis for database queries, how to gracefully get entity class variable names to build query conditions is a common problem. This article will pin...
