Backend on Palmyra

1. Project setup

Mon, 01 Jan 0001 00:00:00 +0000

1. Project setup#

What this step does. Starts a plain SpringBoot project, adds one Palmyra dependency, configures a database, and creates two empty tables. No Palmyra-specific code runs yet — that lands in steps 2 and 3.

`build.gradle`#

plugins {
    id 'org.springframework.boot'          version '3.3.4'
    id 'io.spring.dependency-management'   version '1.1.6'
    id 'java'
    id 'application'
}

java { toolchain { languageVersion = JavaLanguageVersion.of(21) } }
application { mainClass = 'com.example.empmgmt.AppMain' }

repositories {
    mavenCentral()
    maven { url 'https://repo.palmyralabs.com/releases' }
}

dependencies {
    implementation 'org.springframework.boot:spring-boot-starter-web'
    implementation 'org.springframework.boot:spring-boot-starter-data-jpa'
    implementation 'com.palmyralabs.palmyra:palmyra-spring:1.4.4'

    compileOnly         'org.projectlombok:lombok:1.18.34'
    annotationProcessor 'org.projectlombok:lombok:1.18.34'

    runtimeOnly         'org.mariadb.jdbc:mariadb-java-client:3.4.0'
}

SpringBoot entrypoint#

package com.example.empmgmt;

@SpringBootApplication
@Import(PalmyraSpringConfiguration.class)
@EnableJpaRepositories
@EntityScan
public class AppMain {
    public static void main(String[] args) { SpringApplication.run(AppMain.class, args); }
}

`application.yaml`#

spring:
  jpa:
    show-sql: true
    hibernate: { ddl-auto: validate }
  datasource:
    url: jdbc:mariadb://localhost:3306/empmgmt
    username: empmgmt
    password: empmgmt
    driverClassName: org.mariadb.jdbc.Driver

server:
  port: 8080
  servlet: { context-path: /api }

Database tables#

CREATE TABLE department (
  id          BIGINT AUTO_INCREMENT PRIMARY KEY,
  code        VARCHAR(32)  NOT NULL UNIQUE,
  name        VARCHAR(128) NOT NULL,
  description VARCHAR(512)
);

CREATE TABLE employee (
  id             BIGINT AUTO_INCREMENT PRIMARY KEY,
  login_name     VARCHAR(128) NOT NULL UNIQUE,
  first_name     VARCHAR(64)  NOT NULL,
  last_name      VARCHAR(64)  NOT NULL,
  department_id  BIGINT       NOT NULL,
  joining_date   DATE         NOT NULL,
  status         VARCHAR(16)  NOT NULL DEFAULT 'ACTIVE',
  CONSTRAINT fk_employee_department FOREIGN KEY (department_id) REFERENCES department(id)
);

Run ./gradlew bootRun. The app should boot on :8080 with context path /api. Nothing answers yet — we add models and handlers next.

2. Department schema

Mon, 01 Jan 0001 00:00:00 +0000

2. Department schema#

What this step does. Publishes the full CRUD surface for Departments — list, read, create, update, upsert, delete — by writing one Java class plus a model POJO. No SQL, no controllers, no fetch stubs.

Departments are pure master data — small, stable, keyed by a business code (HR, ENG, SALES).

JPA entity#

package com.example.empmgmt.entity;

@Entity
@Table(name = "department")
@Getter @Setter
public class DepartmentEntity {
    @Id @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;

    @Column(nullable = false, unique = true, length = 32)  private String code;
    @Column(nullable = false, length = 128)                 private String name;
    @Column(length = 512)                                   private String description;
}

Palmyra model#

package com.example.empmgmt.model;

@Getter @Setter
@PalmyraType(type = "Department", table = "department", preferredKey = "code")
public class DepartmentModel {

    @PalmyraField(primaryKey = true)
    private Long id;

    @PalmyraField(sort = true, search = true, quickSearch = true,
                  mandatory = Mandatory.ALL)
    private String code;

    @PalmyraField(sort = true, search = true,
                  mandatory = Mandatory.ALL)
    private String name;

    @PalmyraField
    private String description;
}

Notes:

3. Employee schema

Mon, 01 Jan 0001 00:00:00 +0000

3. Employee schema#

What this step does. Adds the second entity — an Employee with a foreign key to Department — and shows off three Palmyra idioms the first entity didn’t need: nested model fields, flattened columns via parentRef, and the preSave lifecycle hook.

Employees carry contact info, a foreign key to Department, a joining date, and a status flag.

JPA entity#

package com.example.empmgmt.entity;

@Entity
@Table(name = "employee")
@Getter @Setter
public class EmployeeEntity {
    @Id @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;

    @Column(name = "login_name", nullable = false, unique = true, length = 128)
    private String loginName;

    @Column(name = "first_name", nullable = false, length = 64) private String firstName;
    @Column(name = "last_name",  nullable = false, length = 64) private String lastName;

    @ManyToOne(fetch = FetchType.LAZY, optional = false)
    @JoinColumn(name = "department_id")
    private DepartmentEntity department;

    @Column(name = "joining_date", nullable = false) private LocalDate joiningDate;
    @Column(nullable = false, length = 16)           private String    status;   // ACTIVE | INACTIVE | RESIGNED
}

Palmyra model#

The interesting bit: the FK to Department is declared as a nested model field. Palmyra resolves the JOIN automatically, and clients can post a partial { "department": { "id": 3 } } to set it.

4. Try it

Mon, 01 Jan 0001 00:00:00 +0000

4. Try it#

What this step does. Exercises the full API with curl — seeding, querying, updating, upserting by natural key, deleting — to confirm the handlers are wired correctly before any frontend code exists.

Restart the app and hit the endpoints with curl.

Seed a few departments#

curl -sX POST http://localhost:8080/api/department \
     -H 'Content-Type: application/json' \
     -d '{"code":"HR",    "name":"Human Resources"}'

curl -sX POST http://localhost:8080/api/department \
     -H 'Content-Type: application/json' \
     -d '{"code":"ENG",   "name":"Engineering"}'

curl -sX POST http://localhost:8080/api/department \
     -H 'Content-Type: application/json' \
     -d '{"code":"SALES", "name":"Sales"}'

List them back:

Backend on Palmyra

1. Project setup

1. Project setup#

build.gradle#

SpringBoot entrypoint#

application.yaml#

Database tables#

2. Department schema

2. Department schema#

JPA entity#

Palmyra model#

3. Employee schema

3. Employee schema#

JPA entity#

Palmyra model#

4. Try it

4. Try it#

Seed a few departments#

`build.gradle`#

`application.yaml`#