Spring JPA 中的@Entity 是什么？
What is @Entity in Spring JPA?
具体来说，我指的是javax.persistence.Entity。
根据我将鼠标悬停在上面时显示的文档，在 VS Code 中它指出：
Specifies that the class is an entity. This annotation is applied to
the entity class.
对于 Spring JPA 来说，class 是一个实体是什么意思？
我四处搜索以找到答案。我决定 post 无论如何，
我抬头
docs.oracle.com 在 post 我的问题之前。
An entity is a lightweight persistence domain object. Typically, an
entity represents a table in a relational database, and each entity
instance corresponds to a row in that table. The primary programming
artifact of an entity is the entity class, although entities can use
helper classes.
实体 class 必须遵循这些要求。
- The class must be annotated with the javax.persistence.Entity annotation.
- The class must have a public or protected, no-argument constructor. The class may have other constructors.
- The class must not be declared final. No methods or persistent instance variables must be declared final.
- If an entity instance is passed by value as a detached object, such as through a session bean’s remote business interface, the class must
implement the Serializable interface.
- Entities may extend both entity and non-entity classes, and non-entity classes may extend entity classes.
- Persistent instance variables must be declared private, protected, or package-private and can be accessed directly only by the entity
class’s methods. Clients must access the entity’s state through accessor or business methods.
另一个有趣的资源是 youtube video
TL;DR: @Entity 注解定义了 class 可以映射到 table.
实体类型的 a class 表示 class，在抽象级别上，它与数据库中的 table 相关。
这个 class 实例化的每个对象表示 table 本身的一个元组，包含后者的信息。
我建议您找出 object relational mapping 是什么。
我还推荐 this page 在 Spring
上谈论 ORM 的（Spring 文档）
具体来说，我指的是javax.persistence.Entity。
根据我将鼠标悬停在上面时显示的文档，在 VS Code 中它指出：
Specifies that the class is an entity. This annotation is applied to the entity class.
对于 Spring JPA 来说，class 是一个实体是什么意思？
我四处搜索以找到答案。我决定 post 无论如何， 我抬头 docs.oracle.com 在 post 我的问题之前。
An entity is a lightweight persistence domain object. Typically, an entity represents a table in a relational database, and each entity instance corresponds to a row in that table. The primary programming artifact of an entity is the entity class, although entities can use helper classes.
实体 class 必须遵循这些要求。
- The class must be annotated with the javax.persistence.Entity annotation.
- The class must have a public or protected, no-argument constructor. The class may have other constructors.
- The class must not be declared final. No methods or persistent instance variables must be declared final.
- If an entity instance is passed by value as a detached object, such as through a session bean’s remote business interface, the class must implement the Serializable interface.
- Entities may extend both entity and non-entity classes, and non-entity classes may extend entity classes.
- Persistent instance variables must be declared private, protected, or package-private and can be accessed directly only by the entity class’s methods. Clients must access the entity’s state through accessor or business methods.
另一个有趣的资源是 youtube video
TL;DR: @Entity 注解定义了 class 可以映射到 table.
a class 表示 class，在抽象级别上，它与数据库中的 table 相关。 这个 class 实例化的每个对象表示 table 本身的一个元组，包含后者的信息。 我建议您找出 object relational mapping 是什么。 我还推荐 this page 在 Spring
上谈论 ORM 的（Spring 文档）