How to create one many relationship in hibernate session

Hibernate One-to-Many Mappings

how to create one many relationship in hibernate session

Hibernate one-to-many relationship tutorial shows how to create a one-to-many hibernate-configuration> session-factory>

Hibernate one to many mapping solutions This problem can be solved in two different ways.

Hibernate One to Many Relationship Example | DevGlan

One is to have a foreign key column in account table i. This column will refer to primary key of Employee table. This way no two accounts can be associated with multiple employees. Obviously, account number needs to be unique for enforcing this restriction. This table will have two column i.

how to create one many relationship in hibernate session

Hibernate one to many mapping with foreign key association In this approach, both entity will be responsible for making the relationship and maintaining it. EmployeeEntity should declare that relationship is one to many, and AccountEntity should declare that relationship from its end is many to one. Design one to many mapping relationship Lets first see the schema design.

Entity classes Write entity classes.

Hibernate one to many mapping annotation example - HowToDoInJava

Hibernate one to many mapping with join table This approach uses a join table to store the associations between account and employee entities. JoinTable annotation has been used to make this association.

how to create one many relationship in hibernate session

Design Lets see how the database schema will look like: Entity classes package hibernate. Hibernate configuration We have available both entities to runtime, we have to add them in hibernate.

And again when we see from employee side, then it is many to one relationship. Maven Project Structure We have 2 model classes - Department.

how to create one many relationship in hibernate session

Maven Dependencies Following are the maven dependencies required to include in pom. So, let us define them first and then we will discuss about the different annotations used in the one to many relationship.

Following annotation configurations is for unidirectional relationship.

Hibernate one-to-many relationship tutorial

For example, in the above Department entity, Department. One thing to observe here is though the relationship is unidirectional, we are not using mappedBy attribute in the annotation JoinColumn because associations marked as mappedBy must not define database mappings like JoinTable or JoinColumn.

In many cases, unidirectional relationship is preferred unless you require to traverse the entity graph from both side of relationship. Bidirectional One to Many Relationships In case of Bidirectional One to many relationship, you have freedom to traverse the relationship from both the direction. Either you can traverse Employee from Department side or you can traverse Department from Employee side.

how to create one many relationship in hibernate session

But above entity configurations is for unidirectional one to many relationship. Let us define bidirectional relationship now.