Entity

Entities are the core part of JPA, representing the data we need to store in our database. Below is an example of an Entity class called User, which defines how the users table is mapped in the database:

package com.fontys.crowdfund.persistence.entity;

import jakarta.persistence.*;
import jakarta.validation.constraints.NotBlank;
import lombok.AllArgsConstructor;
import lombok.Builder;
import lombok.Data;
import lombok.NoArgsConstructor;

import java.util.Set;

@Entity
@Table(name = "Users")
@Builder
@Data
@AllArgsConstructor
@NoArgsConstructor
public class UserEntity {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "id")
    private Integer id;

    @NotBlank
    @Column(name = "name")
    private String name;

    @NotBlank
    @Column(name = "email")
    private String email;

    @NotBlank
    @Column(name = "password")
    private String password;

    @OneToMany(mappedBy = "user", cascade = CascadeType.ALL, fetch = FetchType.EAGER)
    private Set<ProjectEntity> projects;


}

This User entity is annotated with @Entity and @Table to indicate that it is a JPA entity mapped to the users table in the database. Each field is annotated with @Column to define the corresponding columns in the table. The @Id annotation marks the primary key, and @GeneratedValue is used to specify how the ID should be generated (e.g., automatically by the database).