2. Creating JPA entities

This Java code defines a base entity class named BaseEntity that is intended to be extended by other entities in a Java Persistence API (JPA) based application, likely using a framework like Hibernate

package com.eliasmanj.accoutns.entity;  
  
import jakarta.persistence.Column;  
import jakarta.persistence.Entity;  
import jakarta.persistence.MappedSuperclass;  
import lombok.Getter;  
import lombok.Setter;  
import lombok.ToString;  
  
import java.time.LocalDateTime;  
  
@Getter  
@Setter  
@ToString  
@MappedSuperclass  
public class BaseEntity {  
  
  
    @Column(updatable = false)  
    private LocalDateTime createdAt;  
    @Column(updatable = false)  
    private String createdBy;  
    @Column(insertable = false)  
    private LocalDateTime updatedAt;  
    @Column(insertable = false)  
    private String updatedBy;  
  
}

The @Getter, @Setter, and @ToString annotations are from Lombok, and they automatically generate getter, setter, and toString methods for the class, reducing boilerplate code.
The @MappedSuperclass annotation indicates that this class is a superclass for entities and should not be mapped to a database table itself. Instead, its fields will be inherited by subclasses.
Four private fields are defined: createdAt, createdBy, updatedAt, and updatedBy.
Each field is annotated with @Column, providing additional information about how these fields should be mapped to database columns.
@Column(updatable = false) indicates that these columns should not be updated when an entity is modified.
@Column(insertable = false) indicates that these columns should not be included when inserting new records.