Collection Mapping related annotations

Project Implementation of JPA Collection Mapping

Annotations	Definition
@OneToMany	This annotation can be used to define the one-to-many relationship between the two entities. Attributes: mappedBy: it specifies the field in child entity that owns the relationship, and it indicates the inverse side of relationship. cascade: Defines the cascade operation to the applied to associated entities. It allows the propagating the state transitions from parent entity to its associated child entities. fetch: It configures the fetching strategy for the associated the entities. It specifies the associated entities should be the eagerly or lazily loaded from database.
@ManyToOne	This annotation is used to defines the many to one relationship between the two entities. Attributes: fetch: It configures the fetching strategy for associated entity. optional: It indicates whether association is the optional or mandatory. If set to false, then the associated entity must always be present. targetEntity: This specifies the target entity class if the attributes type is the superclass or the interface.
@ManyToMany	This annotation defines the many to many relationship between the two entities. Attributes: mappedBy: It specifies the field in child entity that owns the relationship, and it indicates the inverse side of relationship. cascade: Defines the cascade operation to the applied to associated entities. it allows the propagating the state transitions from parent entity to its associated child entities. targetEntity: This specifies the target entity class if the attributes type is the superclass or the interface.
@ElementCollection	This annotation can be used to define the collection of the basic or the embeddable tables. Attributes: targetClass: This specifies the class of the elements in the collection. fetech: It configures the fetching strategy for the elements in collection. cascade: Defines the cascade operations to applied to elements in the collections.
@JoinTable	This annotation specifies the mapping of the many to many relationships using the join table. Attributes: name: It specifies the name of join table. joinColumns: Defines the foreign key columns of the join table that can reference the inverse entity. inverseJoinColumns: Defines the foreign key columns of the join table that can reference the inverse entity.
@OrderBy	This annotation specifies the ordering of the elements in the collection. Attributes: value: It specifies the property by the which the elements should be ordered. asc: It indicates whether the ordering should be ascending order or descending order.

JPA – Collection Mapping

In Java, JPA can defined as Java Persistence API. Collection Mapping is a powerful feature that allows developers to map relationships between the entities and collections in the database. It allows the developers to map the collections of the objects from Java to corresponding database structures.

Similar Reads

Annotations Definition @OneToMany This annotation can be used to define the one-to-many relationship between the two entities. Attributes: mappedBy: it specifies the field in child entity that owns the relationship, and it indicates the inverse side of relationship.cascade: Defines the cascade operation to the applied to associated entities. It allows the propagating the state transitions from parent entity to its associated child entities.fetch: It configures the fetching strategy for the associated the entities. It specifies the associated entities should be the eagerly or lazily loaded from database.@ManyToOne This annotation is used to defines the many to one relationship between the two entities. Attributes: fetch: It configures the fetching strategy for associated entity.optional: It indicates whether association is the optional or mandatory. If set to false, then the associated entity must always be present.targetEntity: This specifies the target entity class if the attributes type is the superclass or the interface.@ManyToMany This annotation defines the many to many relationship between the two entities. Attributes: mappedBy: It specifies the field in child entity that owns the relationship, and it indicates the inverse side of relationship.cascade: Defines the cascade operation to the applied to associated entities. it allows the propagating the state transitions from parent entity to its associated child entities.targetEntity: This specifies the target entity class if the attributes type is the superclass or the interface.@ElementCollection This annotation can be used to define the collection of the basic or the embeddable tables. Attributes: targetClass: This specifies the class of the elements in the collection.fetech: It configures the fetching strategy for the elements in collection.cascade: Defines the cascade operations to applied to elements in the collections.@JoinTable This annotation specifies the mapping of the many to many relationships using the join table. Attributes: name: It specifies the name of join table.joinColumns: Defines the foreign key columns of the join table that can reference the inverse entity.inverseJoinColumns: Defines the foreign key columns of the join table that can reference the inverse entity.@OrderBy This annotation specifies the ordering of the elements in the collection. Attributes: value: It specifies the property by the which the elements should be ordered.asc: It indicates whether the ordering should be ascending order or descending order....

Tags:

#Java-Spring-Data-JPA #Advance Java

Steps to Implement Collection Mapping

Project Implementation of JPA Collection Mapping