Spring Boot + JPA following Java's camelCase or DB's underscore when naming fields

Discussion

Let’s see this example:

@Entity
public class Member{
    @Id @GeneratedValue
    @Column(name="member_id")
    private Long id;
    
    private LocalDateTime orderDate;
}

Remember LocalDateTime is specially recognised by JPA and adds that field to be mapped to the entity?

Anyway, look at this field name orderDate. The DB prefers name to be ORDER_DATE or order_date with underscores. But Java prefers camelCase like orderDate.

So how should we name it? We optimally want to name it how the DB wants with underscores.

Actually Spring Boot, the latest versions that we are using, addresses this issue. It automatically takes any Java’s camelCase names and edits it to the conventional naming way of DB.

So in this case, even without @Column(name=”order_date), Spring Boot automatically changes the name to order_date and maps it to the entity and saves it to DB.

Cool!