为什么@Table注释在Spring的CRUD操作中是可选的

Question

I am new to spring and spring-boot and while learning Spring CRUD I was going through different articles and I saw these lines.

"And why @Entity annotation is mandatory? … well, it is the way how JPA is designed. When you create a new entity you have to do at least two things annotated it with @Entity create an id field and annotate it with @Id Anything else is optional, for example, the table name is derived from entity class name (and therefore @Table annotation can be optional), table's columns are derived from entities variables (and therefore @Column annotation can be optional), and so on …"

So my question is how spring will bifurcate the tables and their column names if we do not provide @Table annotation and @Column annotations.

Answer 1

As you asked your question in the context of Spring Boot. There are two options that determine the naming strategy:

spring.jpa.hibernate.naming.implicit-strategy

This option is used to determine the names when we don't provide the table and column names explicitly in the entity definition

Usually this defaults to: ImplicitNamingStrategyJpaCompliantImpl

More implementations .

spring.jpa.hibernate.naming.physical-strategy

This is more customizable, pluggable strategy contract for applying physical naming rules for database object names.

By default, a SpringPhysicalNamingStrategy is used where all dots camel casing is replaced by underscores. Also, table names are generated in the lower case.